The Maple Leafs also said backup goalie Garret Sparks is being withheld from competition for precautionary reasons and is being evaluated under the concussion protocol following practice Wednesday.
The Maple Leafs recalled goalies Michael Hutchinson and Kasimir Kaskisuo from Toronto of the American Hockey League on an emergency basis, and Hutchinson made 30 saves in a 4-3 loss to the Minnesota Wild at Scotiabank Arena.
Andersen is in his third season as Toronto's No. 1 goalie. The 29-year-old is 20-9-1 with a 2.50 goals-against average, .923 save percentage and one shutout. Andersen did not practice Wednesday but did skate in full equipment and take shots prior to practice. He worked with goaltending coach Steve Briere and forward Zach Hyman, who is out with an ankle injury sustained Dec. 18.
Andersen last played Dec. 22, when he made 25 saves in a 5-3 win against the New York Rangers.
Coach Mike Babcock said after practice Wednesday he was unsure when Andersen will return.
"He didn't practice, so obviously we're not going to see him tomorrow," Babcock said. "Then we have a practice day in between (before hosting the Vancouver Canucks on Saturday). I don't know if he can practice one day and come [back]. He's practicing every day, he's on the ice and doing his thing.
"He's feeling pretty good, but I don't ask him. When they tell me [he's ready], I'll know."
Andersen backed up Sparks in a 5-4 overtime win against the Detroit Red Wings on Dec. 23 and in a 4-2 win against the Columbus Blue Jackets on Dec. 28 but did was scratched against the New York Islanders the next night in a 4-0 loss, with Kaskisuo backing up Sparks. Andersen missed one game earlier this season, a 4-1 win against the Los Angeles Kings on Oct. 15 because of a knee injury.
Sparks, 25, is 6-2-1 with a 3.01 goals-against average, .905 save percentage and one shutout in 10 games.
The Maple Leafs acquired Hutchinson in a trade with the Florida Panthers on Saturday. The 28-year-old was 1-1-2 with a 4.17 GAA and .839 save percentage in four games for Florida this season. He's 44-40-13 with a 2.70 GAA and .907 save percentage in 106 NHL games with the Winnipeg Jets and Panthers, and has played much of the past two seasons in the AHL.
