The Boston Celtics reportedly are close to a one-year contract with center Jason Collins. The deal would be for the NBA veteran minimum salary, according to ESPNBoston.com, which cited league sources. The 7-foot Collins, an 11-year veteran, would essentially replace center Greg Stiemsma, who is expected to sign an offer sheet with the Minnesota Timberwolves. The Celtics, sources said, are not planning to match the offer sheet. Collins, 33, averaged 1.3 points and 1.6 rebounds in 30 games for the Atlanta Hawks last season. He has career averages of 3.8 points and 3.9 rebounds.