With Tim Thomas taking the 2012-13 season off, the move likely means Rask will be the Bruins' starting goaltender next season.
Rask went 11-8-3 in 23 games last season, with a 2.05 goals-against average and .929 save percentage. However, he suffered a season-ending groin injury in March.
Rask has started for the Bruins previously. In 2009-10, he went 22-12-5 with five shutouts, a 1.97 GAA and .937 save percentage in 45 games. That season, however, ended with him in net in the second round of the playoffs as the Philadelphia Flyers rallied from a 3-0 series deficit to beat the Bruins.
A 2005 first-round pick of the Toronto Maple Leafs, the Bruins acquired him in June 2006 in exchange for Andrew Raycroft. In 102 NHL games, all with the Bruins, Rask is 47-35-11 with 11 shutouts, a 2.20 GAA and .926 save percentage.