As we start to think of this year’s QB class, the question marks continue to pile up.

Unlike last year, with players like Matthew Stafford, Mark Sanchez and Josh Freeman, the top prospects lack ideal size, have major injury concerns and, for some, come from offenses that don’t model anything we see on Sundays.

Is this class flawed? Or more importantly, is this the type of class that could suffer a freefall down the draft board come April?

And let’s not forget about the combine in general, as all of these top prospects, from Oklahoma’s Sam Bradford to Texas’ Colt McCoy, will not be on display for the NFL’s top brass. Instead, they’ll hold their own auditions back on their campuses, where the environment is perfect, down the street from sorority row and only steps from their off-campus apartments. They’ll throw to their own receivers — who know when and how the ball is coming — and these QBs will probably shine.

But what if they don’t, and what if any of these guys has an average to above-average personal workout? How do you justify paying out first-round QB money?

Let’s take a look at the some of the top prospects who will not be throwing this weekend — and the question marks attached to their names.

1. Sam Bradford

The Oklahoma QB has shoulder issues, and although he may check out just fine this weekend, no one has any idea about his rehab and development until we see him throw in Norman, Okla., on his pro day. Played in a spread offense at OU, against Big 12 defenses that are soft — full of Cover 2 schemes and corners who don’t challenge wide receivers at the line of scrimmage. Can he drop back at make all the throws on that fifth step? Can he stay healthy? And if you’re the St. Louis Rams, do you invest $30-million or more up front on a QB coming off a shoulder injury?

2. Jimmy Clausen

Would Clausen be the same high-level prospect if he played at Indiana or Wake Forest, or is he just a product of Charlie Weis’ offensive system at Notre Dame? I like Clausen because he can produce in a pro-style offense, but does he have an NFL arm? Add in the fact that the NFL wants QBs who look and throw like Carson Palmer and it’s hard not to wonder if Clausen can make the throws that every starting-caliber QB does in this league.

3. Colt McCoy

The question mark about McCoy is simple in my mind: Why the sudden desire to pull out of throwing at the combine? This was his time to put his skills on display with the big two of Bradford and Clausen standing on the sideline. Dr. James Andrews said McCoy is a “no go” this weekend. Is this injury worse than it’s being reported in the media? McCoy’s size is an issue, and picking a QB high in the draft who’s 6-2, 210 is a risk. Yes, we can point to Drew Brees, but McCoy only compares to him in size — not ability.

4. Tim Tebow

We already know that Tebow is a project, and the “project” is taking more time to develop as the former Gator is waiting for his pro day to throw while he works on his mechanics. Multiple question marks, a bad Senior Bowl week and time are all against Tebow. Don’t see him as game-ready for a year at the earliest, but he’s still an attractive option for teams that like to be creative. But he’s a backup for now -- and someone you have to be careful with — because you don’t know what you’re getting at the NFL level.

5. Dan LeFevour

LeFevour is all over the place on various draft boards, but if that’s the case, the combine is the perfect place to show the league why his stock should go up. Instead, like the four players mentioned above, he’s opted to throw on campus. Interesting play for a guy who competed in the MAC, struggles to throw down the field and plays in an offense that resembles nothing what we see on Sundays.

Prospects who have a chance to shine this weekend:

With all the QB star power sitting and watching, these players could turn some heads — because they’ll be under the spotlight.

John Skelton, Fordham
Tony Pike, Cincinnati
Jarrett Brown, West Virginia
Jevan Snead, Ole Miss

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