LOS ANGELES -- With the Trojans back to the grind and hard at work at Cromwell Field, here’s a look at some of the early storylines that have taken shape during the team’s volunteer passing sessions.

Tons of talent at WR, not a lot of depth

The USC receiver corps was dealt a significant blow in the second throwing session of the summer when promising freshman Steven Mitchell went down with a torn ACL that will cause him to miss the entire 2013 season. Already without the services of George Farmer -- who suffered the same injury this spring -- the Trojans now have just five active scholarship wide receivers on the current roster.

The good news is that those five players have looked stellar this offseason and, barring any more injuries, USC should be fine here. In particular, 2012 Biletnifkoff Award winner Marqise Lee, and sophomore Nelson Agholor have made a routine of putting on a virtual exhibition during the 7-on-7 drills, and it’s hard to imagine a better wideout tandem in the country. Just as importantly, with the role of the team’s No. 3 receiver still up for grabs, veteran pass-catchers Victor Blackwell and De'Von Flournoy, as well as freshman , have come out each day more focused than ever, paying off with big time results.

Wittek returns to action, QB competition back on in full effect

The most notable player missing from the Trojans' early passing sessions was quarterback Max Wittek, who battled an apparent case of mononucleosis. The only member of the quarterback competition with starting experience returned to action this past Friday and looked sharp after shaking off some early rust.

The other two members of the quarterback competition -- fellow redshirt sophomore Cody Kessler and early entrant freshman Max Browne -- have performed solidly this offseason. Kessler, in particular, has picked up right where he left off in the spring, looking poised and in command while also throwing with fantastic accuracy. Meanwhile, Browne has continued to make tremendous strides, neither looking nor playing like a green first-year youngster.

With Wittek having returned to compete alongside Kessler and Browne, the race for the role of USC's starting quarterback is underway once again. And with all three players back out there pushing each other, there’s reason for optimism, regardless of who the eventual starter is.

Key contributors back from injury

While the loss of Mitchell marked the obvious low point of the workouts so far, the return of a number of players who missed all, or a portion, of the spring due to injury has been one of the great positives. Fullback Soma Vainuku, offensive lineman Chad Wheeler, tight ends Xavier Grimble and Randall Telfer, defensive lineman Greg Townsend Jr., cornerbacks Torin Harris and Kevon Seymour, as well as safeties Dion Bailey, Gerald Bowman and Su'a Cravens are just some of the players who have been spotted back in action. It’s provided a big shot in the arm for a team somewhat short in terms of numbers.

The most talked about return has been that of Bailey, who was out for the entire spring due to postseason surgery to repair a torn labrum in his shoulder. Moving over to free safety after spending the last two seasons as the team’s starting strongside linebacker, he’s looked comfortable, and the competition between he, Demetrius Wright and Leon McQuay III for the starting job is sure to be one of most closely watched position battles of the summer and fall.

Shaw still at safety

With Lane Kiffin underwhelmed by the production of the cornerback unit this past spring, the Trojans head coach noted on more than one occasion that the coaching staff was considering moving redshirt junior Josh Shaw back over from his strong safety spot to corner -- not a huge surprise considering he made seven starts at the position in 2012.

So far, however, there’s been no sign of the former Palmdale (Calif.) standout making that change. Lining up at strong safety during every passing session, he’s currently locked in a position battle with Cravens and Bowman. And while things could always change later in the summer or even during fall camp, it looks as if Shaw has settled in at safety at this time and that Kiffin will ride with what he currently has at cornerback -- collection that includes Anthony Brown, Ryan Dillard, Harris, Chris Hawkins, Ryan Henderson, Seymour and Devian Shelton.

Sightings of the newest freshmen

All six of the Trojans newest freshmen additions are now on campus, and they’ve slowly begun to make their presence felt in the workouts. It was Mitchell who made the biggest impact early on with his unique playmaking skills, giving an all-too-brief glimpse of the kind of talent that the USC offense will have at its disposal down the line. Inside linebacker Michael Hutchings has impressed as well. Figuring to play a key role as the potential backup at the MIKE linebacker spot to Hayes Pullard, he certainly looks the part of an imposing run-stopper with a nice combination of athleticism and instincts to boot. Outside linebacker Quinton Powell has already shown off some nice pass-rush skills during the 11-on-11 periods. At 6-foot-2, 225 pounds, running back Ty Isaac is as big as advertised while also showcasing a surprising burst for a player his size. Rounding out the group, offensive tackle Nico Falah and guard Khaliel Rodgers have also been quick to jump into the action, gaining valuable tutelage from veterans such as Kevin Graf and John Martinez.