Paul Myerberg

USA TODAY Sports

HOOVER, Ala. — Quarterback Nick Marshall's status within Auburn's football program remains undecided following his weekend citation for marijuana possession, Auburn coach Gus Malzahn said Monday.

"Nick made a mistake and he'll have to deal with the consequences," Malzahn said. "I'm not ready to say what those consequences are at this time, but he will deal with it."

Marshall, a rising senior and projected Heisman Trophy contender, was pulled over Friday in Reynolds, Ga., for a window tinting violation. After an odor of marijuana was detected, officers found drug residue inside Marshall's car amounting to less than an ounce – leading to a citation, not an arrest.

Late Sunday, Auburn announced that Marshall would not attend SEC Media Days as one of the Tigers' three player representatives. Instead, Auburn sent tight end C.J. Uzomah.

"It is a privilege and a reward to represent Auburn here at the SEC Media Days," Malzahn said. "Last Friday Nick lost that privilege.

"We have high expectations for our players, but specifically our quarterback, being the face of our program. Up until last Friday, Nick has been a model student, teammate, and citizen. I know he's regretful and he feels very bad about it."

While Marshall's status remains up in the air, another Auburn star might miss the entire coming season.

Malzahn confirmed defensive end Carl Lawson's springtime knee injury – suffered during the last week of drills – was an ACL tear, meaning the sophomore could not return until the latter stages of the regular season, if at all.

A five-star member of Malzahn's first recruiting class, Lawson contributed as a situational rusher as a rookie, finishing second on the team with four sacks. He was expected to assume a far larger role as a full-time starter in 2014, helping Auburn replace end Dee Ford, an All-SEC selection.

The surgery was successful, Malzahn said, adding that Lawson is "working extremely hard and he's determined to come back towards the end of this year."