For years, we've said it's hard to screw it up if you pick a great tackle. The perception was if he can't hack it at left tackle, you could probably move him to right. And if he's still not getting the job done at right tackle, you could always move him inside to guard. So even if you don't maximize the pick, at least you gain some assurances. It's not like you can take a struggling quarterback and make him a starter somewhere else. But at tackle, it was an option.

And yet I still think Greg Robinson, as special as he is, could be a risky pick if he's taken as high as No. 2 overall by St. Louis.

I consider Robinson a risk not because I'm convinced he'll initially struggle, but because the one area where he'll need to improve is the single greatest reason you should draft him high: pass protection. Robinson went to Auburn as a guard, and while his conversion to tackle was successful, coach Gus Malzahn's offense allowed Robinson to do what he does best, which is overwhelm opponents as a run-blocker who could bury the edge, take defenders where he wanted at the point of attack, and move down the field with his quick feet and hit would-be tacklers in space.

But where Robinson still needs work is as a pass-protector, where there are kinks to be ironed out. So if you determine he's your pick in St. Louis, Jacksonville or even Oakland, you're doing so with the belief that he'll improve your pass protection right away, because those are teams that can't afford an injured quarterback. Robinson can be special, but only if he develops in pass protection. That seems like a given, but when you consider where he could be taken, it's a big bet.

Mel Kiper Jr. has been ESPN's NFL draft expert for more than 30 seasons and has published a draft report for 35 years. He also can be found on Twitter @MelKiperESPN.

I'll go with Oklahoma State cornerback Justin Gilbert for this one. He was a really difficult evaluation to do because there are a lot of really good qualities to his game. At the end of the day, what coaches want most out of their defenses is to produce takeaways, and Gilbert is great at it. He has excellent hands -- it's like he's Jerry Rice out there sometimes.

Not only that, he's an outstanding playmaker with the ball in his hands, both after coming up with a turnover or in the return game. He had two interception returns for touchdowns in 2013, and six career kickoff returns for TDs. His straight-line speed is excellent, as he proved at the combine with a 4.37 40-yard dash.

On the other hand, I have some concerns. I see a lot of tightness in his hips in coverage, particularly when he is forced to cover quicker wide receivers. He gives up a lot of separation on hard-cutting routes and double moves. The bigger issue, however, might be his tackling. He simply isn't a physical player; he isn't going to come up and provide run support, and he's going to miss a lot of tackles when trying to bring down wide receivers after the catch.

For those reasons, he carries with him a good deal of risk, especially for teams in the 8-15 range that might be looking for a cornerback. That's why I have him ranked third among cornerbacks on my board, behind Michigan State's Darqueze Dennard and Virginia Tech's Kyle Fuller -- two guys who don't possess the same straight-line speed but are steadier and more physical.

Todd McShay is the director of college scouting for Scouts Inc. He has been evaluating prospects for the NFL draft since 1998. Follow McShay on Twitter @McShay13.