NFL Combine 2012: Players Who Can't Afford to Have Bad Workouts

Prospects who dominate the NFL scouting combine are not locks to be great players at the pro level. Similarly, players who fall flat at the combine are not doomed to a life of professional irrelevance.

Nevertheless, it is at least a good idea for prospects to perform well at the combine when they get there. They stand to help or hurt their draft stock, ultimately helping or hurting their wallets.

This year, there are a couple prospects who stand out as being in need of a good showing at the combine. Let's discuss five in particular.

Quinton Coples, DL, North Carolina

The primary concern regarding Quinton Coples is how reliable his motor is. He's going to be a high first-round pick based on his physical tools and his athleticism, but it's going to be difficult for him to silence concerns about his desire.

Coples can help silence those concerns in the interview process, but that won't matter if Coples disappoints in the workouts. He needs to show off speed and agility, two things that are vital to Coples if he wants scouts to view him as an elite pass-rusher.

If Coples shows that he's not all he's cracked up to be, he'll start to slide down big boards in a hurry. He has little to gain at the combine, but a lot to lose.

Alshon Jeffery, WR, South Carolina

Alshon Jeffery is a big dude. Since there aren't many wide receivers who can match his size, that's a good thing.

However, Jeffery's size won't matter if he doesn't show that he can run. He'll beat anybody in a jump-ball situation, but that won't do him much good if he can't get behind the defense.

The 40-yard dash is the most overrated event at the combine, but Jeffery's performance in the 40 will make or break his draft stock. If he runs well, he'll be a first-round pick. If he doesn't run well, he'll start to slide. Next thing you know, you might hear talk about how he needs to be converted into a tight end.

Luke Kuechly, ILB, Boston College

Everyone knows Luke Kuechly can tackle. He racked up hundreds of them during his career at Boston College.

What people are less certain of is how athletic Kuechly is. Scouts love his instincts, but he may not have the athleticism to be a difference-maker at the next level.

If you ask Clifton Brown of The Sporting News, it's a simple matter of Kuechly showing scouts that he's faster and more agile than he's supposed to be. If he is, that means he'll be able to make plays in the pros, particularly in pass coverage.

If Kuechly doesn't impress, he's another guy who will start to slide.

Chris Polk, RB, Washington

It's a given that Trent Richardson is going to be the first running back taken in the draft. He's a beast.

The question is who will be the next running back off the board: Lamar Miller or Chris Polk?

Between the two of them, Polk has more to prove. He didn't have a very impressive week at the Senior Bowl, and some scouts are concerned Polk just isn't quick enough to cut it in the NFL. Steve Muench of ESPN.com wrote this week that Polk just doesn't look as explosive in real life as he does on film.

The 40-yard dash will be important for Polk, and so will the agility drills. Polk won't completely fall flat in either area, but anything less than impressive performances will be a bad thing. Polk needs to show he's worth a first-round pick. If he doesn't, he'll slide.

Brandon Weeden, QB, Oklahoma State

Andrew Luck and Robert Griffin III will be at the combine, but both of them have little to prove. 

Brandon Weeden, on the other hand, has a lot to prove. He impressed in his college career and he impressed at the Senior Bowl, but he needs to keep impressing.

Weeden basically needs to show he's worth a significant investment despite his advanced age. He's already 28, but a team will take a chance at him if he shows off a strong, accurate arm in workouts. He'll also have to wow scouts in the interview process.

Weeden stands to elevate himself into first-round territory. If he doesn't impress anybody at the combine, he'll stay right where he's at.