Markeith Ambles not at USC practice

LOS ANGELES -- Receiver Markeith Ambles was absent from USC's Saturday practice at the Los Angeles Memorial Coliseum and did not inform the coaching staff of his whereabouts, coach Lane Kiffin announced after the session.

Ambles, a sophomore, has had a troubled first year at USC. Since arriving on campus last summer, he has been suspended, left the team and been forced to miss multiple practices and do extra conditioning drills as punishment for late arrivals and no-shows to team functions.

"He wasn't here this morning," Kiffin said Saturday. "It went on as normal, so we'll figure it out."

Ambles, 19, was punished earlier in the week for arriving late to a mandatory team weightlifting session and was not allowed to practice on Thursday, instead running repeatedly around Howard Jones Field during the Trojans' practice.

He had previously been suspended in October and, shortly after his reinstatement two weeks later, left the team in November and went home to suburban Atlanta for several weeks over the Christmas break before meeting with Kiffin and deciding to rejoin the team in mid-January.

Kiffin said Saturday he was worried about Ambles' behavior. He and fellow sophomore Dillon Baxter were involved in a number of incidents together in 2010 but Baxter has managed to stay out of trouble this spring.

"You'd like to see guys continue to mature, like some of the other freshmen," Kiffin said of Ambles.

Pedro Moura covers USC for ESPNLosAngeles.com.