Draft eligible players report to Indianapolis Wednesday for the annual NFL scouting combine. The Raiders have the fifth overall pick and have much to consider as to who they use that precious pick on. Few teams can afford to blow a top five pick, but the new regime in Oakland has great pressure to bring in playmakers.

Among those players worthy of being picked in the top five, several will have things to prove at the combine. Not only must they prove they are indeed worthy of a high pick, but for the Raiders purposes, they must prove they are a good fit.

The players take the field to show their physical prowess on Saturday. But before that, there will be interviews after interviews where players must prove they have the character NFL teams are looking for.

Of the top picks, none will be more heavily scrutinized in the character department than Johnny Manziel and Jadeveon Clowney.

Manziel's partying ways has been a cause for concern for a while now. Recently he directly had his character come into question by the notorious character assassin, Nolan Nawrocki, who had this to say about Manziel:

"Suspect intangibles -- not a leader by example or known to inspire by his words. Carries a sense of entitlement and prima-donna arrogance seeking out the bright lights of Hollywood. Is known to party too much and is drawn to all the trappings of the game. ... Has defied the odds and proven to be a great college-system quarterback, but still must prove he is willing to work to be great, adjust his hard-partying, Hollywood lifestyle and be able to inspire his teammates by more than his playmaking ability."

Manziel must somehow put those concerns to rest. He also must put concerns about his unwillingness to sit in the pocket and deliver the football as the NFL often demands. He has said he won't be throwing at the combine, instead waiting to throw at his pro-day workout. That is not a good sign, but teams will overlook it if he shines at that pro-day. If he were to blow it at the combine, they would be less likely to overlook it.

Clowney has been accused of lacking the mental makeup to be a great NFL player. In a conference call Tuesday, NFL Network draft analyst, Mike Mayock expressed his as well as some GMs' concerns with Clowney's character.

"I know that he's got the physical makeup to be the best player in the draft. If you want to compare him to Mario Williams, I think he's a better football player with more upside than when Mario came out of college and he was obviously the first pick. "So from a physical skill set, this kid is as freaky as they come. He plays a position of critical importance in today's NFL which is an ability to get the quarterback. He can play multiple places on the defense, so all those things check off. "My biggest concern is just what's his mental makeup and how important is it to him when he gets a big paycheck to become the best player in football, or is he just going to be happy to be a millionaire. "So I think that's the most critical checking point here from an organization is finding out what the motivation, what kind of kid are they going to get. I know what the football player is when motivated. I just want to know what kind of kid I'm getting."

Others who have something to prove at the combine are quarterbacks Blake Bortles and Teddy Bridgewater.

The combine was practically invented for guys like Bortles. He looked great in college, putting up big numbers as a passer but at Central Florida he didn't face a lot of top tier competition. At the combine scouts will be able to analyze everything he does in a vacuum. He has been compared to Ben Roethliseberger and the combine will go a long way to helping prove or disprove that comparison.

Bridgewater was an incredibly accurate passer in college and is admired for his ability to run a pro style offense at Louisville. The big, glaring concern for him is arm strength. He has an odd delivery which doesn't appear to be ideal for an accurate long ball. If he can't disprove the belief that he lacks elite arm strength, he will be seen as a game manager. That's an ugly term in NFL circles.

The next seven days will be boring for the casual NFL fan and tantalizing for the NFL geeks who love to crunch numbers on measurements and things like 40-yard dash times, bench presses, and 3-cone drills. Once it's over, this meat market style parade should go a long way to shaping how the draft plays out.

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