The first week of season-long fantasy baseball is officially in the books, and even if you're looking your wounds after a tough loss, there's a lot of game left to go. We know that fantasy baseball is a marathon, and that's displayed by the fact that most teams have played just five games, or approximately 3.08% of their regular season schedule thus far.

However, you will find several owners ready to push the panic button already.

Perhaps you're one of these owners -- it happens to the best of us. If you're not sure whether you should hold or fold on a player, that's why we're here.

The following 10 players have seen a perceived change in their fantasy stock through the first week of the MLB season, we'll attempt to decipher which ones warrant taking action this early. Some may seem premature, but that is the goal -- to be ahead of the rest of your league.

Hold Masahiro Tanaka

Did you invest an early-round pick in Masahiro Tanaka following his strong 2016? Feeling a bit like the beloved dog from the "This is fine." meme? Already receiving low-ball offers and texts from your leaguemates reminding you of the threat of re-injury to the UCL he injured in 2014?

Let's take a step back here. Breathe. Everything is going to be okay. This is fine.

This is still the man who ranked third in ERA and fifth in WHIP in the American League last year. His career 3.26 ERA is backed up by a nearly identical 3.27 xFIP. The dude is legit. You knew this going into the draft, just as you already knew about his injury concerns. Nothing has changed.

So, how can we explain Tanaka's 11.74 ERA through his first two starts? Well, it could be as easy as chalking it up to a small sample size, but let's take a deeper look.

For starters, opposing hitters have a .462 BABIP against him. That's nearly 100 points higher than the next pitcher who has made two starts and is up almost 200 points from his career average of .273. The inflated BABIP especially stands out when you consider Tanaka has not been hit hard -- he's allowing opponents to post just a 25% hard-hit rate. According to FanGraphs.com, not a single ball was hit "hard" against Tanaka in his last five-inning start.

Where he has struggled has been his command, which is unusual. He has a career walk rate of 4.5%, so it seems likely that this is a blip on the radar rather than the beginning of a trend. While he has struggled some to find the zone, batters have had an equally tough time making contact against him. Batters have a 67.9% contact rate against him, which is the ninth-best among starting pitchers and is well below his career 76% mark. He has also missed bats with regularity, posting a 16.4% swinging-strike rate that ranks sixth among starting pitchers and is up from his career mark of 11.9%.

The injury concerns will always be there for Tanaka, but let's not act as if he has regressed as a pitcher after just two starts. The stuff is clearly there for him, he just needs to find his control. If you're a Tanaka owner, your best option is likely to weather the storm and wait for the returns you expected when you took him with an early pick.

Sell Yasiel Puig

He's back! After seemingly everyone had given up on Yasiel Puig this offseason, the fantasy community is ready to jump back on the bandwagon following an opening week that saw him post a batting average of .292 with 3 home runs, 5 runs scored, and 5 RBI. Well, not to rain on the parade, but virtually all of that production came in two games against Jered Weaver and Trevor Cahill. Outside of that, he has hit 3-for-17 with four strikeouts.

It is fun to get excited about a hot first week from Puig and ignore reality. But the once-tantalizing prospect is now in his fourth major league season and has never put together a season with more than 20 home runs, 70 RBI, or 15 stolen bases.

The party has to come to an end at some point, right?

A deeper look at his numbers suggests the rude awakening might be closer than Puig owners would like to admit. Puig's struggles have never been pounding opposing fastballs, but rather being able to identify offspeed pitches. That hasn't changed this year, as evidenced by the table below comparing his whiff percentage against the soft stuff this year to his career numbers, courtesy of brooksbaseball.com.

He has seen slightly better numbers against cutters and sliders, but overall still has alarming whiff rates against offspeed pitches as a whole. Until he improves his contact rate against offspeed pitches, it seems unlikely he will be able to take the next step and reach the potential everyone envisioned him having.

This isn't to say that Puig won't rebound from last season's disappointing performance or outperform his draft stock. Don't feel the need to dump him to the first owner who sends you an offer. Rather, if you have an owner who still envisions Puig as the promising talent we saw upon his arrival to the league, don't be afraid to take advantage of his hot start.

Hold Gary Sanchez

Gary Sanchez took the league by storm during last season's fantasy playoffs, launching 20 balls into orbit over just a 53-game span. That projects out to a perhaps not-so-attainable 61-dinger pace over a 162-game season, so you can see why many were excited to reach for such a potential difference maker at catcher.

Well, 2017 couldn't have gotten off to much worse start, as he posted a .150 batting average with a 4-to-1 strikeout-to-walk ratio through five games before going down with a bicep injury to his throwing arm. He was placed on the 10-day disabled list and currently has no timetable for a return. Not great, Bob!

At this point, you're not going to get anything other than low-ball offers for Sanchez, especially since nobody really knows the extent of his injury. So, all you can really do is sit and wait.

While you wait, here are some numbers that should reassure you his slow start was nothing more than bad luck over a small sample size.

Among players with at least 20 plate appearances, only seven have posted a worse BABIP than Sanchez's .133 mark. None of said players have a hard hit rate anywhere near Sanchez's 43.8% mark. Considering Sanchez posted a BABIP of .317 with the Yanks last season and never posted a BABIP below .280 in six seasons in the minors, it is fair to assume Sanchez's BABIP was a fluke.

Buy Sean Manaea

Sean Manaea entered the season with as much hype as any late-round starting pitcher, but after watching him give up nine runs through 11.1 innings over his first two starts, many owners might be ready to cut bait.

While the ERA through two starts certainly isn't encouraging, the peripherals surrounding it are. Manaea has struck out 14 batters so far, which gives him a 28.6% strikeout rate, while also generating a 19.1% swinging-strike rate over that same time. His swinging-strike rate ranks first among starting pitchers thus far.

These numbers are nothing new for the former prospect, as Manaea posted an 11.8% swinging strike rate last year that was higher than the likes of Stephen Strasburg, Madison Bumgarner, and Chris Sale. Among pitchers with at least 100 innings in 2016, none induced swings at a higher frequency than Manaea.

Manaea struggled to find his footing in 2016 as well, but settled in to post a 2.44 ERA and 0.99 WHIP over his final 13 starts. The dude has tons of talent, which is quite evident when looking at his strikeout numbers. If the Manaea owner in your league is ready to jump ship, make sure you're the one to take advantage.

Drop Byron Buxton

Sigh. I want Byron Buxton to be good. I really do. But unless you're in deeper leagues or ones that reward you for striking out, it is hard to justify rostering him for much longer.

The one-time top prospect has looked completely lost at the plate through the first week, which brings back painful memories from the past two seasons for Twins fans and Buxton truthers. He has seemed determined to one-up his atrocious 35.6% strikeout rate from last season, posting a 51.9% mark through five games -- the highest in the league by a wide margin.

He's not just striking out, though -- he's swinging at everything. His 60.8% swing rate is the fourth-highest in the league and is up from his career mark of 47.1%. He's also swung at pitches outside of the zone 45.6% of the time, which is the 10th-most in the league. His 26.2% swinging-strike rate is nearly double his career mark and is the second-worst in the majors. It's been really ugly, guys.

It is hard to part ways with someone with as much hypothetical upside as Buxton. We've seen this before, though. For all his tools, Buxton has consistently looked overwhelmed at the plate at the major league level. With several appealing waiver-wire options available, perhaps it is time to move on from Buxton.

Add Manuel Margot

Whew! What a first week from Manuel Margot! The 22-year-old outfielder has been everything the San Diego Padres could have hoped for thus far, posting a .286 batting average with 2 homers, 4 runs, 4 RBI, and a stolen base.

Perhaps even more impressive than his numbers is the path he has taken to get them. The list of pitchers Margot has faced thus far includes Clayton Kershaw, Bumgarner, Johnny Cueto, Rich Hill, and Kenta Maeda, to name a few. He's also hit leadoff or second in every game he's started, regardless of who was on the mound.

Margot has looked capable of handling the best the majors has to offer, posting a 36.4% hard-hit rate while only swinging at 25% of pitches outside of the zone. He is still available in over 50% of ESPN leagues, a number which is quickly on the rise.

Sell Aledmys Diaz

Aledmys Diaz came out of nowhere last season to post strong enough numbers that the St. Louis Cardinals had no choice but to make him their every-day shortstop. With quality numbers across the board through the first week (.296 batting average, 2 homers, 5 runs, 4 RBI, and 2 stolen bases), he seems poised for an encore to his breakout rookie season, right?

Well, maybe not quite. Let's take a look.

While Diaz's numbers look great on the surface, he has shown a disturbing lack of plate discipline thus far. He has been swinging at nearly everything thrown at him, posting the highest swing rate in the league. He's swung at 47.1% of the pitches he's seen outside of the strike zone, which is the third-highest. He's also posted a 12.7% strikeout rate, which is up from 7.4% last season. Diaz also has yet to walk through 27 plate appearances.

Perhaps he can be the exception to the rule, but generally, hitters can't sustain a batting average anywhere near .300 while applying such a free-swinging approach at the plate. Also, after being caught on four of eight stolen base attempts last season, Diaz's two stolen bases through six games seem more like an aberration than anything else.

This isn't to say Diaz is a bad hitter or is due for a sophomore slump -- his plate discipline numbers could certainly be a product of small sample size rather than a new development to his approach at the plate. If someone in your league is willing to buy in to his hot start, though, don't be afraid to pull the trigger.

Hold Edwin Encarnacion

It seems pointless to include a player of Edwin Encarnacion's caliber here, but there were plenty of whispers of caution about his advancing age and offseason move away from the Rogers Centre and a loaded Toronto Blue Jays lineup. So, it is reasonable that you could find yourself worried by his .217 batting average and 30.8% strikeout rate. There doesn't appear to be much reason to worry, though.

Encarnacion is one of the league's premier hitters, boasting an average line of .272, 39 homers, 90 RBI, and 110 RBI over the past five seasons. What has been the issue for Encarnacion to start 2017?

Well, for the most part, it would appear to be bad luck. Encarnacion has absolutely crushed the ball to begin the season. He has posted a 53.3% hard-hit rate, as well as a 46.7% fly-ball rate, both of which are higher than his career averages and make him one of just six hitters with a mark of over 45% in both categories. The hits are coming, and based on his fly-ball rate, a good portion of them could be home runs.

Don't let one subpar week cause you to sell Encarnacion for less than he is worth. The balls will start finding holes soon enough, and his numbers will begin to represent the dominance we've become accustomed to over the past half decade.

Add Kendall Graveman

Just one year removed from battling for a rotation spot, Kendall Graveman has fully looked the part of an ace for the Oakland Athletics through two starts. Following an impressive seven-strikeout performance on opening day, Graveman carried a no-hitter into the seventh inning against a dangerous Texas Rangers squad on Saturday. The overall result is a sparkling 2.08 ERA and 0.85 WHIP, along with a 25% strikeout rate.

As our own Tom Whalen pointed out, Graveman's velocity has been up across the board to begin the season. If he is able to maintain this, the improvements in strikeouts could be the new norm for Graveman.

He's currently only owned in 26% of ESPN leagues, a number that is sure to go up. His next scheduled start is against a Houston Astros team that has struggled offensively to begin the season and finished last season with the fourth-highest strikeout rate against right-handed pitching. If he is able to rack up the strikeouts again, he likely won't be on the waiver wire for much longer.

Drop Yulieski Gurriel

Despite a fairly disappointing 2016 major league debut, many felt inclined to take a chance on Yulieski Gurriel's upside in this year's draft. The early returns have not been encouraging, as Gurriel boasts a .095 batting average and 14.3% strikeout rate.

Similar to Buxton, Gurriel has looked like a fish out of water at the plate -- in 21 plate appearances so far this year, he's posted a 64.9% swing rate and 45.2% swing rate on pitches outside the zone.

The right-handed hitter has also been fortunate enough to face left-handed starting pitchers in four of his five games, yet has still struggled. A platoon seems imminent if he continues to struggled at the dish. To make matters even worse, Gurriel has yet to hit any higher in the order than the six spot.

He's worth keeping an eye on, but Gurriel has yet to show us anything that makes him worth rostering. Feel safe to drop him in all but the deepest of leagues.