The Boston Celtics have signed free agent center Jason Collins and re-signed guard Keyon Dooling.

The team also announced Tuesday it had signed two guards who played in Europe last season, Jamar Smith and Dionte Christmas.

Collins, an 11-year veteran, has averaged 3.8 points and 3.9 rebounds in 12.3 minutes in his career with New Jersey, Memphis, Minnesota and Atlanta. With the Hawks last season, he averaged 1.3 points and 1.6 rebounds in 10.3 minutes.

Dooling, a 12-year veteran, averaged 4.0 points and 1.1 assists in 14.4 minutes last season, his first with Boston.

via The Associated Press