The Eagles play their final preseason game of the year on Thursday, and all eyes will be on the battle for the third string quarterback job. Incumbent Matt Barkley and challenger Tim Tebow have been locked in a tight contest, with all signs pointing to Tebow getting the nod when the roster is whittled down to 53 players this weekend.

Despite reports to the contrary, head coach Chip Kelly has said that he needs to see both quarterbacks in another game before making his final decision on who to keep. But there are some compelling reasons why Kelly should consider going against the grain and part ways with both quarterbacks.

Talent

The conversation really revolves around Tebow, but it makes sense to start first with Barkley. Drafted in the fourth round of out USC in 2013, Barkley has shown nothing to indicate that he's capable of being anything more than a bottom-of-the-roster player. His lack of arm strength has been well documented, but that's not even necessarily the biggest issue.

Through three preseason games, Barkley has a 66.6 quarterback rating, zero touchdowns and one interception on 43 pass attempts. And while he has had his moments (his first drive of the first preseason game was solid), he has yet to show that he should be anything more than a third-stringer. And earlier this offseason, reports indicated that the Eagles' brass is looking to move on from Barkley entirely.

Which brings us to Tebow. Among all quarterbacks who have thrown a pass this preseason, Tebow ranks exactly one position higher than Barkley in quarterback rating at 67.2, good for 78th overall. Tebow has run for a score and hasn't thrown an interception, but he has also missed open receivers and shown a general lack of passable NFL quarterbacking ability.

Tebow does possess good athleticism and above average speed for his position. But as the third quarterback, he would not be asked to serve as the running back - if he's in the game, the Eagles will have the horses to run the ball. Does Tebow have the ability to lead his team and win a meaningful game? Part of his legend is that he's answered questions like this one with a resounding "yes," but the bigger question here has more to do with whether that scenario is worth a roster spot at all.

Game Day Fit

If the Eagles do indeed keep Tebow, he will more than likely be inactive on game day. As Brandon Lee Gowton pointed out on 'Breakfast on Broad' this morning, Kelly has not had three quarterbacks active since arriving in Philadelphia. That means even if the catastrophic happens and both Sam Bradford and Mark Sanchez go down in the same game, Tebow wouldn't be eligible to play anyway.

There are a couple scenarios in which the Eagles could cut bait with Barkley and Tebow and still go into the season with more than two quarterbacks. If the Eagles do in fact release Barkley, he still has practice squad eligibility. The Eagles could bring him back on the practice squad and call him up if the need arises.

Tebow is in a similar situation. After being out of the league all of last year and not exactly shining this preseason, it's possible Tebow could remain unsigned during the regular season. If that happens, the Eagles could give him a call if one of their quarterbacks goes down.

And speaking of bringing players back, G.J. Kinne is still eligible for the practice squad in 2015. Though he was training at wide receiver this offseason, he has been at quarterback the previous two years, and could make an interesting option. If a quarterback goes down during the season, for example, the Eagles could promote him to the active roster and even use him on special teams as well.

The other option could come through the free agent market. Robert Griffin III could be released soon, and while he is not likely going to want to be a third stringer in Philly, the Eagles are reportedly interested. And what about a player like EJ Manuel, who has been relegated to the third string in Buffalo? If cut, he could elect to take a year and learn from the Chip Kelly Experience before returning to the open market.

Value

Ultimately, the biggest question here is value. Ask yourself this - who would you rather have as the third quarterback: Kinne or Tebow? If the answer is "I don't care" or "it doesn't matter," doesn't that say everything you need to know about Tebow's value–or any third-string quarterback's value–to the team?

It will be up to the Eagles to decide whether they think a player like Tebow or Barkley is more valuable than another deep bench player like Ed Reynolds II or John Moffitt. The team can only dress so many players for a game, and if Kelly and his coaching staff decide that positional versatility trumps quarterbacking ability, Barkley and Tebow could be on the outside looking in.

So while it seems that the Eagles have made up their mind about keeping three quarterbacks, it isn't necessarily as simple as keeping Tebow (or Barkley) for the sake of having an emergency option at quarterback.