If you haven’t heard of Kevin Kiermaier, it’s time to start paying attention. Kiermaier spent April and May being shuffled between Triple-A Durham and the Tampa Bay Rays, providing outfield depth for a banged-up group of starters. When Wil Myers went down with a wrist injury, Kiermaier was again recalled, although this time with a chance for increased playing time. He’s now played 48 games and has 170 plate appearances this season, far from a large sample size, but he’s played well enough that he now has a stranglehold on Myers’ vacant outfield position.

Kiermaier’s line at the break is .310/.349/.576 with eight home runs and 24 runs batted in. Considering he was called up primarily for his defense, the offense he’s provided to a team that’s struggled to score runs this season (the Rays are 19th in total runs scored) has been a welcome surprise.

Statistically, he’s actually been the best player for the Rays this season. His 2.8 Wins Above Replacement is tied with Desmond Jennings for the team lead, and his Runs Above Average (wRAA) of 11.3, a stat which “measures the number of offensive runs a player contributes to their team compared to the average player,” is almost four full points higher than the next best player for the Rays, (David DeJesus at 7.4).

Again, 170 plate appearances is a small sample size, but Kiermaier’s Runs Created plus (wRC+) is among the league’s best. His wRC+ of 160 is good for ninth-best among players with 170 or more plate appearances, and would rank sixth-best among qualified hitters. Just for reference, Jose Abreu, Paul Goldschmidt, and Giancarlo Stanton all currently have a lower wRC+ than Kiermaier (albeit in many more plate appearances).

Kiermaier has shown surprising power at the plate as well, and his .266 Isolated Power (ISO) would be seventh-best in all of baseball if he had enough plate appearances to qualify. It’s 11th-best for players who have a minimum of 170 plate appearances. He’s hitting home runs at a high clip, as his home run to fly ball ratio (HR/FB) of 20.5% is 14th highest in baseball among hitters with at least 170 plate appearances. However, this number is skewed because of his lack of at bats.

Kiermaier has only hit 39 fly balls this year and managed to turn eight of them into home runs. It also doesn’t help his case that of the 13 hitters ahead of him by HR/FB, none is hitting fly balls at a lower percentage that his 32.8%. Further hurting Kiermaier’s case for this ratio to maintain its current pace is the fact that he’s never been much of a home run hitter. In 433 career minor league games, he hit a total of 15 home runs, and never more than five in a single season. His career high for home runs in a single season at any professional level has come in his first 48 games in the big leagues. Keep that in mind.

All signs point to the high rate at which he's hitting home runs to regress, and while his eight home runs do help inflate his ISO, he has 14 other extra-base hits (10 doubles and 4 triples) helping his cause. He’s a strong runner as well, which suggests a potential for singles to be turned into extra bases. While league-average changes year-to-year, FanGraphs estimates that an “average” ISO is .145.

Kiermaier would need to fail to record an extra-base hit in roughly his next 130 at-bats before his ISO would become “league-average.” While it’s not likely that his hits in his next 130 at-bats will only be singles, it’s also unlikely that he’ll finish the year as a “league-average” hitter when judging by ISO. More importantly, the Rays must be thrilled to get that kind of production from a defensive outfielder who’s only playing in the show because of injuries, and they are already rewarding him.

When Kiermaier started receiving regular playing time, he hit toward the bottom of the lineup. From June 28th until July 9th, he only hit higher than ninth once, and that was seventh. However, coming off of a game in which he batted last but went four for four with a grand slam, Kiermaier found himself batting leadoff the next day. He remained in that spot going into the break, and in his three games hitting leadoff he went 5 for 10.

As numberFire contributor Jim Sannes pointed out yesterday, Kiermaier struggles to hit lefties, but crushes righties. If he can figure out how to hit south-paws as well, there’d be no reason to move him back to the bottom of the lineup. It’s possible that Kiermaier was temporarily filling in for Desmond Jennings who was given a few days off after fouling a ball off his knee, but either way, Kiermaier is giving manager Joe Maddon a difficult decision to make once the break is over.

Kiermaier made the Rays’ roster because of his glove, but his bat may prove to be the reason he sticks around. He’s already shown how valuable a player he is, as his 2.8 Wins Above Replacement would rank 35th best in baseball if he had the at-bats to qualify. Even if his .345 batting average on balls in play, to go along with just a 16.0% line-drive percentage, suggest that he’s been getting “lucky” and that he’s just on a hot streak, Kiermaier is worth an add in fantasy leagues. He’s barely owned in Yahoo! (just 8% as of this writing), meaning that there's virtually no risk to adding him and riding out his streak if that’s all this is.

Our projections for the remainder of the season don’t look favorable for Kiermaier, but right now his bat is too good for the Rays to sit down even when they get healthy (Myers is expected back in mid-August). If Kiermaier is able to replicate his first 48 games played, fantasy owners and the Rays’ front office will be celebrating together.