Zach Mettenberger isn't one of the top quarterback prospects in this year's draft, but it wouldn't be a shock to see the former LSU standout, a 6-foot-5, 225-pounder, hear his name called sometime in the first three rounds.

But Mettenberger was found to have a diluted sample at the NFL combine's drug test, and about 36 hours before the draft's first round is to begin, NFL.com reported Wednesday morning that a number of NFL teams have medically flagged him because of a back condition called spondylolysis.

Mettenberger hasn't needed -- and reportedly won't need -- surgery for the condition that flared up during the 2012 season. LSU trainer Jack Marucci told Ian Rapoport that altered mechanics, thanks to former Ravens offensive coordinator and current LSU OC Cam Cameron, helped make the condition less of an issue in 2013.

"Did it flare up in his career? Yes. We would treat it and he'd be fine," Marucci told NFL.com. "It wasn't something we thought was a chronic disc or something. He doesn't need surgery. There's no surgery for it. He's worked with our doctors. This shouldn't be a big deal as long as you treat it, we did some core stabilization. His senior year, we didn't even talk about it."