The Crimson Tide's Achilles' heel

AJ McCarron and Phillip Sims threw four total INTs in Week 1. Greg McElroy had four in all of 2009. US Presswire

The Alabama Crimson Tide entered this season needing to replace five starters from last year's team.

Four of those lost starters were taken in the first round of the NFL draft. The other one, however, might be the most difficult for the Tide to replace in their quest for the 2011 BCS title.

To be clear, Alabama doesn't have another Julio Jones, and it doesn't have another Marcell Dareus. There's a reason those guys were top-10 picks. Bama is looking at a couple of solid options to ultimately fill the vacancy left by James Carpenter at left tackle, and people have been saying for two years that Trent Richardson is every bit as good as Mark Ingram at running back.

But filling the shoes at quarterback might be a different story.

Scouts would tell you that AJ McCarron and Phillip Sims are more physically gifted than Greg McElroy, and they certainly were more highly recruited than their predecessor. But it takes more than height and arm strength to make an effective QB, and failing to match McElroy's success in one critical area could prove problematic for the Tide.