Talent isn't the question. Matthew Stafford, Mark Sanchez and Josh Freeman -- the presumptive top three quarterbacks of this year's draft -- have plenty of talent.
What they don't have is a whole lot of big-time football experience.
Entering the NFL as juniors, Stafford, Sanchez and Freeman have caused concern that they aren't ready to play at the next level. The assessment of more than a few scouts, general managers and coaches in the league is that the three quarterbacks should have remained in college for another season, just as the rookie sensations of a year ago -- Matt Ryan of the Atlanta Falcons and Joe Flacco of the Baltimore Ravens -- did.
Much of that is based on thorough study of game tape of what Stafford, Sanchez and Freeman displayed during their respective collegiate careers at Georgia, USC and Kansas State. But a good deal of it also stems from recent cautionary tales of highly touted quarterbacks who were drafted as juniors and wound up struggling in large part because they weren't ready for the NFL.
That still might not discourage the Detroit Lions from using the No. 1 overall pick on Stafford, who brings exceptional intelligence along with a rocket-launcher for an arm. But it should at least make the Lions pause and reflect on the potential downside of an investment of more than $30 million in guaranteed cash.
So should the mostly terrible track record of first-round quarterbacks drafted as juniors and redshirt sophomores. Just look at the last three years. JaMarcus Russell, whom the Oakland Raiders made the No. 1 overall pick in 2007 after his junior year at LSU, has struggled his way into a make-or-break season. Vince Young, whom the Tennessee Titans made the third overall pick in 2006 after his junior season at Texas, will enter his fourth NFL training camp the same way he finished his third pro season -- as a backup to 36-year-old Kerry Collins. Alex Smith, whom the San Francisco 49ers made the No. 1 overall pick in 2005 after his junior season at Utah, will enter his fifth NFL training camp as the understudy to Shaun Hill, who wasn't even drafted.
Sure, Ben Roethlisberger has won two Super Bowls since joining the Pittsburgh Steelers as the 11th overall pick in 2004 after his junior season at Miami of Ohio. Sure, Drew Bledsoe and Trent Dilfer qualify as success stories after entering the league as juniors.
But they're vastly outnumbered by the juniors-turned-NFL-flops, such as Rex Grossman … and Tim Couch … and Ryan Leaf … and Heath Shuler. The most notable redshirt sophomore to enter the league is Michael Vick, whom the Atlanta Falcons made the No. 1 overall pick in 2001. His career has been on hold since he ended up in jail because of his role in a dogfighting ring, but his football future has its share of lingering questions because of his run-first tendencies.
Young seemed to be leading a charmed existence when he went from leading the Longhorns to a national championship to starting for the Titans. After 13 starts as a rookie, Young was selected to the Pro Bowl and made the cover of the Madden football video game, largely because of the excitement he generated with his feet rather than with his passing arm.
But Young later revealed that he had contemplated retirement after his rookie season because of the enormous pressure he felt. He appeared to regress as a passer during 15 starts in 2007. Then, in 2008, the bottom fell out. Young left the Titans' season opener with a knee injury, raised concerns about his emotional well-being when booing from the home crowd caused him to suffer a meltdown and never regained the starting job from Collins.
Of the multiple negative labels that coaches and GMs around the league have privately applied to Young the past few years, the one heard most often is "immature." It's another way of saying he wasn't ready to handle the challenges presented by playing quarterback in the NFL. He wasn't ready to read complex coverages or handle the wide variety of ways that NFL defenses pressure the quarterback.
As Titans coach Jeff Fisher told reporters during the NFL Annual Meeting last month, Young still has plenty of work in front of him and "is in a situation now where he will have to do everything he possibly can to earn his (starting) job back." Fisher talked about the importance of Young making the "offseason commitment" to improve his game and that he and the rest of the Titans' coaching staff would do all it could to "get him back in a position to help us win." But the coach also made it clear that, in re-signing Collins before he could hit the free-agent market, the Titans committed to him as their starter.
For the most part, Young has been forced to rely far too heavily on his tremendous running ability because he has yet to demonstrate that he understands how to consistently be an effective passer.
Draft series: Quarterback
 Don't miss NFL.com's look at the QBs in the draft.
"He can't read coverages, so he just runs around," said an AFC coach whose team has faced Young. "You can get away with that in college. But with a pro offense, you have to be able to react to the coverage and instantly translate it to your arm. It's got to be bang-bang and you get the ball out. You don't see Young do that very often."
Fisher has witnessed firsthand the added hardships a quarterback can face when entering the NFL as an underclassman. Young's experience seems to have given Fisher a greater appreciation of the importance of getting maximum exposure at the collegiate level.
"The position is a difficult one to play, especially for a young player," Fisher said. "You don't know how they're going to respond day to day, week to week -- how they're going to deal with the pressure. Not the Sunday pressure, but the Wednesday, Thursday, Friday pressure.
"That's where there is more pressure on the quarterback than Sunday -- pressure to go out and execute properly on the practice field. If the quarterback throws four interceptions against the scout-team defense on Wednesday, your team is affected. His ability to deal with that early, and a staff's ability to create a situation where he's having fun, is going to be directly related to the success he has."
The moral of this cautionary tale for prospective NFL quarterbacks: Sticking around for your senior year might not be such a bad idea.