The nature of NFL free agency in an era of a rising salary cap is that some players are going to wind up getting contracts that sound absurd at first. We haven't adjusted our minds yet for the increase in money, so it's hard to grasp that a player could possibly be worth as much as he nets.

Some potential deals, though, are just bonkers.

Free agency is a hell of a drug.

Mike Glennon has started 18 games in his NFL career, none of which have come in the past two years as he has spent the time backing up Jameis Winston for the Tampa Bay Buccaneers. This is the same Mike Glennon who was benched in favor of Josh McCown back in 2014. And now, he's primed to have a higher base salary than Cam Newton, Drew Brees, Russell Wilson, and Aaron Rodgers.

This is an apples-to-oranges comparison because Glennon is on the open market, but the projected salary is mind numbing.

Because Glennon started back in the day, we do have a decent amount of data on which to judge him as an NFL quarterback. Before scoffing at any potential deal, it's only right to go back to that time and see how Glennon performed to find out if teams know something our perception of Glennon forces us to overlook.

To do this, we'll be using numberFire's Net Expected Points (NEP), the metric we use to track the efficiency of both teams and players. For Glennon, we'll be looking at his Passing NEP per drop back, which shows the expected points he was able to generate on each drop back throughout the season. There's a big difference between a three-yard completion on 3rd and 2 and the same completion on 3rd and 4, and NEP helps quantify those differences while also deducting points for incompletions, interceptions, and sacks.

Is it possible we're missing something on Glennon that justifies such a bulky salary? If we are, it's not in the numbers.

A Justifiable Benching

The Bucs didn't waste time tossing Glennon into the fire, rolling him out as their starter in Week 4 of his rookie season. Glennon's play reflected it.

In 456 drop backs that season, Glennon racked up a whopping -23.43 Passing NEP, equating to -0.05 Passing NEP per drop back. That ranked 28th out of the 39 quarterbacks who had at least 200 drop backs, putting him behind prolific names such as Kellen Clemens, Matt Cassel, and Matthew McGloin.

Even more concerning was his Success Rate, which measures the percentage of drop backs that result in positive NEP. Glennon's Success Rate was 41.89%. Not only did this put him 34th in the league in this stat, but it was lower than Terrelle Pryor, who may simultaneously be hitting the free-agent market this year -- as a wide receiver.

Glennon did make strides in his second year as a starter, but his numbers were still wholly unsatisfactory. This table shows his NEP metrics in his two years as starter compared to the league averages for quarterbacks in that season. Does this look like a guy who deserves $14 million per year?

In both seasons, Glennon was at least a tenth of a point worse than the league average per drop back, and his Success Rate was around five percentage points lower. That's not a stellar track record.

Perhaps the one thing working in Glennon's favor is that McCown struggled on the same offense after taking over in 2014. A quarterback's efficiency also depends on the play of his pass-catchers and offensive line, and this may indicate that Glennon's numbers were being dragged down by a poor supporting cast.

This should allow us to conclude that Glennon is better than McCown. Additionally, Glennon will be entering his age-28 season, which certainly isn't hurting his cause. But with McCown earning just north of $4 million with the Cleveland Browns last year, a $10-million gap between the two seems far fetched.

The issue here is that plenty of teams need quarterbacks this year, whether through free agency or the draft. So if they're not burning money in the Glennon sweeptstakes, they need to find an arm somewhere else. Even in this year's draft class, that shouldn't be a problem.

Finding an Alternative

This year's draft class has a lack of star power at the top with each incoming rookie presenting some major statistical flaws. And -- as we've seen before -- collegiate efficiency stats do matter for quarterbacks. You would assume Glennon would be a better option than rolling the dice in the draft.

However, the sample we have on Glennon thus far in the NFL is far from satisfactory, so that experience may not present him with an edge over the group. But if we go back and look at Glennon's collegiate resume, it may tell us that he's a better prospect than those coming up the pipe.

Instead, it does exactly the opposite.

Here's Glennon's statistical profile coming out of North Carolina State back in 2013 compared with a mystery member of the 2017 draft class, dubbed Player X.

The "Games Played" category represents the number of games in which the player had at least 10 pass attempts (one of the more predictive marks for quarterback prospects), and each of the efficiency stats is from the player's final season at his school. "AY/A" stands for adjusted yards per attempt, which factors in raw yards per attempt while accounting for touchdowns and interceptions thrown. Which would you rather have?

Player X had 11 additional games of experience and whooped Glennon's tail in efficiency. This would make it seem obvious which is the better prospective NFL player.

Player X is Miami's Brad Kaaya, who will likely be a day-three selection in the upcoming draft. Glennon, meanwhile, may be one of the richer quarterbacks in the game. Giddy up.

This isn't to say that Kaaya -- or anybody else in the draft -- is definitively a better option than Glennon. But the information we have on Glennon now is that he has struggled in a limited sample size in the NFL, he was benched in favor of an older veteran, and he had a poor resume coming out of college. That is what you're getting if you dabble in these waters in the coming weeks.

Money That's Hard to Comprehend

The scarcity of quality quarterbacks in the NFL is always going to drive prices up on players, especially those who are young enough to present some sort of upside. Outside of his age and height, though, it's hard to see what makes teams clamor over Glennon.

If a team is in need of an upgrade at the quarterback position, their best plan of attack may be to side with an older, cheaper option. Even though Glennon is young, he hasn't shown reason for optimism, and two years of riding the bench likely haven't changed that.

If there are no other satisfactory options in free agency, then the draft could be the optimal outlet.

Even though it is a weak class, there are players who will be available late who have better statistical profiles than what Glennon had coming out of college. These players will also come with a lower opportunity cost due to low draft capital and bargain salaries. This would allow the team to bolster its passing offense via investment in wide receivers and the offensive line with the money they would have otherwise thrown Glennon's way. Given his limitations, that would seem to be the more fruitful route.

Glennon has a role in the NFL, but it doesn't seem to be as a high-level starter. If his salary were to reflect this, then bringing him in via free agency would make more sense. However, a $14-million contract is not that of a back-up, and paying such a hefty load is hard to justify.