Looking at the spring football depth chart: offense

Spring practice begins a week from today for USC. Let's delve into a little bit of what we can expect from the 15-practice schedule, going position by position through USC's offense and expectations for each. Alphabetically, we dive into the significant players at each spot. We'll have defense tomorrow.

QB: Matt Barkley, Mitch Mustain, John Manoogian, Brett Kan

Barkley, a sophomore, is the clear favorite to start at quarterback, despite coach Lane Kiffin's comments that every position would be up for grabs during practice. Mustain has thrown only 16 passes in a USC uniform but did win all eight of his starts as a true freshman at Arkansas. Manoogian and Kan are walk-ons who will vie for the third-string quarterback spot — at least until incoming freshman Jesse Scroggins begins to practice with the team in the summer. Something to watch: the number of reps Mustain gets on a daily basis during spring practice. That, in itself, will tell a great deal.

RB: Dillon Baxter, Allen Bradford, C.J. Gable, Curtis McNeal, Marc Tyler

Bradford is expected to get the majority of carries this season, but there's room for Gable, Tyler and McNeal to find their way into the rotation. Baxter will be auditioning at multiple positions this spring, including running back. Bradford broke through in 2009, running the ball 115 times for 668 yards and eight touchdowns, but Gable fell through the cracks, earning just 24 carries. McNeal and Tyler both possess considerable talent, as products of Los Angeles-area Venice and Oaks Christian high schools, respectively.

FB: Stanley Havili, D.J. Shoemate, Hunter Simmons

Havili is the clear-cut starter, with Shoemate his backup. Said running backs coach Todd McNair of Havili in the USCRipsIt preview: "I expect him to continue to push to get better and become an all-around great fullback." Simmons is a walk-on. With Kiffin calling plays this year, it'll be interesting to see how/if he incorporates Havili into the passing game. The senior to-be has caught at least 22 passes in each of his previous seasons at USC.

WR: David Ausberry, Dillon Baxter, Brice Butler, Brandon Carswell, De'Von Flournoy, Ronald Johnson, Travon Patterson, Kyle Prater

This will be the position to watch this spring, as the Trojans attempt to replace Damian Williams, who left school early for the NFL draft. The favorites to start alongside the clear No. 1 Johnson are Ausberry and Butler. Ausberry has every physical attribute you'd want in a pass-catcher — the Spring Prospectus calls him USC's "most physical receiver" — but his hands are questionable at best. Reports out of team workouts have Ausberry practicing some at tight end, where his 6-foot-4, 235-pound frame may be better suited. Butler isn't as physical, but his routes are more crisp and his work ethic is strong.

Either way, both Ausberry and Butler will be counted on as key targets for Barkley. Other receivers who have something to prove this spring include Prater and Flournoy. The 6-foot-5, 200-pound Prater graduated a semester early from Proviso West (Ill.) and has may be the best combination of size and speed among the receivers. Flournoy, at 6 feet, 180 pounds, has the potential to be a threat the way Williams was for the Trojans. Both Patterson and Carswell were highly regarded recruits out of high school who've yet to fulfill expectations at the college level. Patterson's a speedster-type, Carswell, a junior who has started three games in his USC career, is a more balanced receiver.

TE: Blake Ayles, Jordan Cameron, Rhett Ellison

One of these three will earn the starting tight end spot by the time spring practice is over, but it could very well be snatched from them by any one of the trio of incoming freshmen tight ends (Xavier Grimble, Randall Telfer and Christian Thomas). Cameron's switching over from receiver for spring practice. Between the two others, Ellison has more experience, having started six games in his career, but Ayles is more talented. The two combined for just 13 catches for 128 yards in 2009.

OT: Martin Coleman, Kevin Graf, Matt Kalil, Tyron Smith

Smith started most of last season; Kalil replaced him in the Emerald Bowl when he became academically ineligible. Together, the two will be the projected as bookend tackles — at least in spring practice. Then all-everything offensive line signee Seantrel Henderson arrives on campus in the fall to compete for one of the spots. Coleman, a junior to-be, has been severely hampered by injuries in his USC career. Graf redshirted as a true freshman last season.

OG: Zack Heberer, Khaled Holmes, Butch Lewis, John Martinez

Lewis will come into spring practice as a starter at one guard spot. Holmes and Heberer will be the heaviest competitors for the other position. Heberer, a senior t0-be, started five games in the 2008 season but lost out to Alex Parsons for a starting position a year ago. Holmes, a Mater Dei High grad, is a redshirt sophomore to-be who has appeared in only three games as a Trojans.

C: Abe Markowitz, Kristofer O'Dowd, Michael Reardon

O'Dowd was a standout his first two seasons at USC, earning Preseason All-American honors before last season but struggled to rebound from injury. He started just seven games, willingly giving away his starting spot to Jeff Byers near the end of the year. Reardon was named Service Team Offensive Player of the Year last season but has hardly logged game time on the offensive line. Markowitz is a walk-on who moonlights on the track and field team.