In the days before spring practice begins on March 5, TrojanSports.com is previewing a USC position group. We continue with offensive linemen.

Returning: Clayton Bradley, RS Sr.; Jacob Daniel RS, Sr.; Frank Martin RS Jr.; Bernard Schirmer RS, Jr.; Austin Jackson, Jr.; Andrew Vorhees, Jr.; Jalen McKenzie RS So.; Brett Neilon RS So.; Alijah Vera-Tucker RS So.; Justin Dedich, RS Fr.; Liam Douglass, RS Fr.

Lost: Chris Brown; Chuma Edoga; Toa Lobendahn

Added: Gino Quinones

Arriving in summer: Tilini Livai, Jason Rodriguez

1. What difference will reassigned OL coach Tim Drevno make over the course of a full year?

2. Who’s going to start at left guard, center and right tackle?

3. Will USC’s next star lineman please stand up?

Neilon vs. Dedich: There will be open competition at at least three spots. This is the one that intrigues me most right now because I think it’s probably the tightest, and it’s at a position that was such a sore spot last year. Neilon was ready to take on more than the one start he was given – perhaps only JT Daniels had more job security on offense than Lobendahn -- while Dedich redshirted because he wasn’t needed yet. But the staff has intimated he might have the higher ceiling. USC hasn’t featured a true center since Kris O’Dowd in 2010.

It was within reason to expect that last year’s offensive line was going to be good. Four starters were returning, including three seniors, and the projected fifth, Jackson, was thought to have the most potential. That term gets you in trouble, though.

While each individual might have played well at certain points of the season, and health wasn’t a notable issue, the quintet never molded into anything resembling a strong collective. Their immobile QB was regularly under duress, and the run game was as poor as it’s been in at least 12 years. You’d like to believe things can only go up from here, but the returning cast still has a lot to prove.