Allison, injured Saturday night against Montreal, underwent the procedure on Tuesday. He won't play again this season as the recovery time is six weeks.
The 30-year-old Allison ranks second on the team with 60 points,
including 43 assists. He has 76 penalty minutes and a minus-18
rating in 66 games this season.
The loss of Allison is another big blow to the Maple Leafs, who
entered Thursday in 11th place in the Eastern Conference
standings, seven points out of the eighth and final playoff spot
with 10 games remaining. Toronto announced last Thursday that
goaltender Ed Belfour would miss the rest of the season with a
An All-Star with Boston in 2001, Allison has recorded 154 goals
and 331 assists in 552 career games with Washington, Boston, Los
Angeles and Toronto.
The Associated Press and SportsTicker contributed to this report.