AUBURN -- Mario Fannin's versatility has been a blessing - and maybe a curse.The Auburn senior has been all over the football field the last three years, lining up as a wide receiver, H-back, backup running back, Wildcat quarterback and return man, and has done it so much he is on the cusp of surpassing a 1,000 yards in receiving, rushing and kickoff returns.But Fannin may actually be set to settle down in his old age.He's an honest-to-goodness tailback in his final college spring."Sometimes,'' he said of playing many roles, "it can be a bad thing, but I look at it as a good thing to be able to have that versatility that the coaches want to put you anywhere."But now that I'm mainly focusing on one thing. I feel like I'll be a better running back now rather than being focused on so many positions.''The glamour position at Auburn has been tailback, and Fannin is getting the first shot at winning the position vacated by Ben Tate."It's a blessing being able to play tailback at Auburn. There have been a lot of great guys who have come through here, so being part of that tradition is big,'' Fannin said.His spring-time competition is Onterio McCalebb, the little change-of-pace runner who probably doesn't have the size to be an every-down back; and Donate Aycock, the redshirt who coach Gene Chizik said a month ago would assume Fannin's multiple roles, but threw him directly into the tailback competition before spring began.Whoever is in there, McCalebb says "it should be a good combination. Mario is a good back. He's a leader, too. I look up to him.''Lurking in the shadows is Michael Dyer, the prize of the signing class in February. He'll be the buzz in August when fall practice begins, just as new quarterback Cam Newton is the buzz this spring.But an old-timer like Fannin can't be dismissed. He has rushed for 971 yards in his career, including 285 last season. That isn't an eye-popping number, but maybe this is.He averaged 8.4 yards per carry."We don't,'' said running backs coach Curtis Luper, "have anyone that has taken a significant amount of snaps at tailback. That's a priority for us to find someone who can do what Ben did for us or it may take two guys to do what he did. We'll find out over the next 15 workouts where we are with that.''Fannin was the receiving back and Tate was the runner. Fannin was the second-leading receiver with 42 catches for 413 yards. Tate was the leading rusher with 263 carries for 1,362 yards.Fannin sizes up his role last season as a "split-time thing.''"Any time they wanted me there, I could play it.''Now, it's the tailback position, the same one Tate is going to parlay into an NFL contract. Fannin acknowledged he also has a chance to cash in a big senior year."But at the same time you can't let it be on your mind right now,'' Fannin said. "You can't really look at that aspect right now. That comes after the season. Right now, it's more of a team thing.''