The NFL Draft is in a month, and as has been the case in recent years, quarterbacks are the hot commodities. In my most recent mock draft here at CBS Sports, I have three teams selecting QBs in the top five, and it's entirely possible we could see four taken in the first five picks when the dust settles. Now more than ever, quarterback has become the "must have" in the NFL.

Nevermind the fact that we just saw the Eagles lose their franchise quarterback to a torn ACL only to go on to win a Super Bowl with a third-round pick out of Arizona named Nick Foles; the prevailing theory is that to compete for Super Bowls, you must have a franchise QB.

The problem is there might not be a position in sports that's harder to project from the amateur level to the professional. We see players who were great in college flame out in the NFL all the time, but it just happens with a greater frequency at quarterback because the position is about so much more than measurables.

So if four QBs are taken in the first five picks next month, there's a good chance only one of them will emerge as a good quarterback in the NFL. Some might prove to be average, backups or out of the league after their first contract. And it's that distinct possibility that inspires this week's Friday Five.

This week, I'm ranking five QBs who were good in college, were drafted in the top five, and then just never found it in the NFL. I'm limiting the pool to quarterbacks since the beginning of the BCS era, and also to players who are no longer in the league. Even with those restrictions, there are still plenty of options available to me because, as I said before, QBs bust frequently.

5. Robert Griffin III, Baylor (No. 2 overall, 2012): We start with a Heisman Trophy winner. RG3 was one of the driving forces behind the surge of Baylor's football program in this decade, winning the Heisman in 2011 while throwing for 10,366 yards and 78 touchdowns in his career. He was selected with the second pick of the 2012 NFL Draft by the Washington Redskins, one pick after the Indianapolis Colts took Andrew Luck.

The Redskins paid a heavy price for Griffin as well, sending three first-round picks and a second rounder to the Rams to move up to No. 2. Oddly enough, the Redskins drafted Kirk Cousins in the fourth round as well.

Griffin's NFL career started well, as he won the AP Offensive Rookie of the Year in 2012 after a terrific debut. Injuries would begin piling up the following season, however, and Griffin found himself without a team in 2017 after starting five games for the lowly Cleveland Browns in 2016. While his career was cut short more by injuries than performance, I include him on this list due to the high price the Redskins paid to get him.

Now, here we are six years later, and RG3 is out of the NFL, and Kirk Cousins just left Washington for a lucrative deal with the Vikings.

4. Tim Couch, Kentucky (No. 1 overall, 1999): Couch was the first lesson a lot of NFL teams were going to learn over the next two decades. Couch was the quarterback at Kentucky when Hal Mumme and a little-known offensive coordinator named Mike Leach brought an offense to college football that hadn't been seen at that level yet.

In the Air Raid offense, Couch put up ridiculous numbers with the Wildcats, throwing for 8,159 yards and 73 touchdowns while completing 69.36 percent of his passes in his final two seasons in Lexington. Those numbers helped lead the Browns to take him with the first pick of the 1999 Draft, and as things tend to happen with Browns quarterbacks, it did not work out well.

Couch started 59 games for the Browns over five seasons, and while the completion percentage remained at a respectable 59.8 percent, he threw 67 interceptions to go with his 64 touchdowns.

3. Ryan Leaf, Washington State (No. 2 overall, 1998): Leaf's name is practically synonymous with the term "NFL Draft bust," but I'm only putting him at No. 3 here for a couple of reasons.

First of all, he was a major bust. The Chargers took him at No. 2, and the months leading up to the draft were one long debate between Leaf and Tennessee's Peyton Manning. Well, the fact Manning went on to become one of the best quarterbacks in NFL history made the debate look a lot dumber in hindsight, and played a role in how big of a bust Leaf was perceived to be.

Secondly, Leaf was never all that great to begin with if you look at his college numbers. While he had a solid season in 1996 with Washington State, Leaf's only "great" season was in 1997 when he threw for 3,968 yards and 34 touchdowns. When you look closer, though, you see that Leaf only completed 53.8 percent of his passes in college. That was a red flag that was ignored because of his size and arm strength, as teams were too busy looking at measurables and projecting what he might be rather than what he was. It's something NFL teams continue to do -- cough, Josh Allen, cough -- and sometimes it works. Most times it doesn't.

Leaf fell into that latter group, as he started only 21 games in the NFL, completing 48.4 percent of his passes. Combined with off-field issues, Leaf's career was a short one.

2. JaMarcus Russell, LSU (No. 1 overall, 2007): Remember the movie "Napoleon Dynamite?" Remember how in the movie the character Uncle Rico bragged he could throw a football clear over those mountains? Well, I'm pretty sure Russell could throw a football over the Rockies. Russell had a howitzer and showed it off with frequency at LSU, passing for 5,572 yards and 43 touchdowns over his final two seasons. For his college career, he completed 61.9 percent of his passes.

And, as I alluded to, he could throw a football like a million yards.

So the Raiders took him with the first pick of the 2007 draft hoping he'd be throwing bombs and leading the Raiders to the playoffs for years. He didn't. Instead, Russell barely managed to complete half his passes in the NFL and threw 23 interceptions with only 18 touchdowns.

His NFL career lasted three seasons with 25 starts, and he was out of the league following the 2009 season.

1. Vince Young, Texas (No. 3 overall, 2006): If we're going simply by the "bust" metric, Young doesn't deserve to be No. 1 on that list. But this is my list, and I have him here for a very specific reason.

I thought Vince Young was amazing in college, and I was convinced he'd continue to awe me in the NFL. It never quite happened.

In six NFL seasons -- five with the Titans -- Young started 50 games. He threw for 8,964 yards, 46 touchdowns and 51 interceptions while completing 57.9 percent of his passes. He also rushed for 1,459 yards and another 12 touchdowns, but while he showed flashes of the brilliance he displayed while at Texas, he was never consistent enough as a passer to make it work out.

We'll always have the 2006 Rose Bowl, though.

Honorable Mention: David Carr, Fresno State (No. 1 overall, 2002); Joey Harrington, Oregon (No. 3 overall, 2002); Akili Smith, Oregon (No. 3 overall, 1999); Mark Sanchez, USC (No. 5 overall, 2009)