RALEIGH — The returning stars of N.C. State’s football team were front and center at Tuesday’s practice, the first of the 2012 season.

Senior quarterback Mike Glennon and junior cornerback David Amerson led the Wolfpack, coming off an 8-5 season, through a back-to-work, summer-is-over, practice in shorts and helmets for two-and-a-half hours.

There were some notable additions, namely safety Tim Buckley, a Penn State transfer, but also some significant absences. Running back Mustafa Greene, backup quarterback Tyler Brosius and defensive tackle A.J. Ferguson did not participate in practice because of academic-related issues.

“They’re still working to get themselves on the football field,” sixth-year coach Tom O’Brien said. “So, we’ll see if they make it or not.”

Greene, a sophomore, hasn’t played since the Pack’s Champs Bowl win over West Virginia in Dec. 2010. The team’s leading rusher as a true freshman, he missed the entire 2011 season with a foot injury.

He returned briefly in the spring only to run into disciplinary trouble with O’Brien. The coach said last week at the ACC Kickoff that Greene was going through summer workouts and was expected to contend for playing time with returning running backs James Washington and Tony Creecy but Greene was missing on Tuesday.

There’s not set timetable for his return, O’Brien said.

“He has to continue to do what he’s supposed to, then he would be able to get out here and practice,” O’Brien said. “If he doesn’t, then he won’t be here.”

Brosius backed up Glennon last season and is listed in the media guide in the same spot for this year. The third-year sophomore completed eight of 13 passes for 66 yards and a touchdown last season.

If Brosius doesn’t return, true freshman Manny Stocker would likely be Glennon’s backup. Stocker enrolled in January and has impressed the coaches with his leadership.

Colorado State transfer Pete Thomas was another new face at practice but Thomas has to sit out the season under NCAA rules. Thomas started two seasons for the Rams and threw for a total of 4,269 yards.

Thomas wore No. 6 on Tuesday as did Buckley, who left Penn State’s program after the NCAA hit the Nittany Lions with a four-year bowl ban for the fallout from the Jerry Sandusky scandal.

Buckley, who played his high school ball across the street from Carter-Finley Stadium at Cardinal Gibbons, redshirted at Penn State last season. A backup free safety for the Lions in the spring, O’Brien was impressed by Buckley.

“He’s got a chance to get himself in the two-deep (depth chart),” O’Brien said. “We were fortunate enough that he wanted to come home and play for us.”

O’Brien said he had reached out to first-year Penn State coach Bill O’Brien before Buckley made his decision. N.C. State has been in contact with other Penn State players, who are allowed to transfer without having to sit out the year.

The Wolfpack coach did not rule out the possibility of other PSU players transferring to Raleigh.

“If they continue to talk to us and they wanted to make a move, then (Bill O’Brien) didn’t have a problem with that,” the Pack coach said.

Linebacker Robert Caldwell, a junior college transfer, also missed practice because his paperwork with the NCAA was still being finalized, O’Brien said.

The comings and goings didn’t dampen the enthusiasm for the start of a season of high hopes. With 14 starters and both specialists in the fold, the players are thinking bigger than the predicted third-place finish in the Atlantic Division.

But before the Wolfpack can run, it has to get through training camp. As far as starts go, O’Brien was pleased. He reiterated this is his “deepest” and “most experienced” team.

Asked if his sixth team would be his best, O’Brien said: “We’ll find out.”

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