BASKETBALL

National Basketball Association

BOSTON CELTICS — Signed F Glen Davis.

FOOTBALL

National Football League

TAMPA BAY BUCCANEERS — Signed LB Jeremiah Trotter to a one-year contract. Released WR Taye Biddle. Signed WR Michael Spurlock to the practice squad.

COLLEGE

BOSTON COLLEGE — Signed Al Skinner, men's basketball coach, to a contract extension through the 2012-13 season.

NEBRASKA — Signed Bill Callahan, football coach, to five-year contract extension through January 31, 2012.