SAN DIEGO -- Oakland Raiders All-Pro center Barret Robbins was sent home by the team before yesterday's Super Bowl for unspecified violations.

A Raiders spokesman declined to comment on why Robbins was disciplined, but various Web sites reported that he missed Saturday's walk-through practice and showed up late for the team's final meeting Saturday night.

A Sun reporter saw Robbins leaving Tijuana, Mexico, on Saturday when team events were occurring.

"It was no distraction because I eliminated it," Raiders coach Bill Callahan said. "He was essentially dismissed. He missed some responsibilities and obligations. I made a decision to dismiss him for that."

Adam Treu started in Robbins' place. The six-year veteran had not started this season, but he did start the final 14 games last season when Robbins suffered a season-ending knee injury.

Robbins was nicknamed "The Jerk" by his teammates for his surly disposition. But he was an integral part in making the line calls during games.

Although the Tampa Bay Buccaneers sacked quarterback Rich Gannon five times last night, most of the pressure came off the edges rather than up the middle against Treu.

"It didn't help our cause," Gannon said. "But I don't know if he would have made any difference."

The Associated Press and other news organizations reported that Robbins was hospitalized yesterday. Two sources, speaking on condition of anonymity, said Robbins was expected to spend the night in a hospital after he left the team for nearly 24 hours during the weekend.

Robbins, who had what the team called a "chemical imbalance" during the 1996 season, was hospitalized in the San Diego area, the sources close to Robbins said.

The Associated Press contributed to this article.