The superstar centre won't need surgery but his absence removes the team's top scoring threat from the lineup. Sundin has 19 points (8-11) in 17 games and the 36-year-old was especially hot in the last five games with nine points (3-6).
"Just the way we've been playing since the start of the season, I'm not really worried about it," Sundin said during a conference call. "We've been getting production from pretty much four lines and we're going to need that as we go on. It's a long season and you're going to have injuries. . . .
"Personally it's just disappointing not to be able to play at this point. I think we're starting to do some good things as a team and starting to create an identity and creating good habits and it's tough in that way."
Sundin suffered the injury in the first period of Monday's 4-1 victory over the Philadelphia Flyers when he took an awkward hit in the offensive zone. He was able to finish the game but an MRI Tuesday revealed a partial ligament tear.
"I didn't really make much of the hit, I didn't even fall down, but it kind of got my arm in the wrong way," said Sundin. "It hurt when it happened. Sometimes you get hit, you get a stinger and it kind it goes away.
"It stayed with me for the rest of the game."
Maple Leafs general manager John Ferguson said it's up to other forwards to step up now, much like the defence did in the absence of injured blue-liners Pavel Kubina, Andrew Wozniewski, Carlo Colaiacovo and Staffan Kronwall.
"Brendan Bell and Ian White along with Hal Gill and Tomas Kaberle and Bryan McCabe especially - they were not only able to get us through that but really come through for us," said Ferguson. "So this is going to be an opportunity up front. You don't replace Mats, but it is going to be an opportunity for others to demonstrate their abilities to handle more.
"Handle more responsibility, handle more ice time and be difference makers for us."
Darcy Tucker is Toronto's second-leading scorer with 16 points (10-6) in 17 games, followed by Kaberle (13 points), and Alexei Ponikarovsky, Kyle Wellwood and Matt Stajan (12 points apiece).
The Leafs are at Boston on Thursday followed by a home game with Montreal on Saturday. Then the Leafs get a bit of break, off until Nov. 16 at Boston.
Sundin missed 12 games early last season after he suffered a fractured lower orbital bone when his left eye was struck by a puck in the season opener.
He came back to score 31 goals and 47 assists in 69 games, his 78 points tops on the club despite missing time.
"It's kind of similar to last year. I was really looking forward to this season and getting off to a good start. It's disappointing," he said. "I felt really good, as good as I've felt through the first 17 games of the season. I'm looking to make this as short as possible. . . .
"It could have been a lot worse. It looks like I'm not going to need surgery or anything.
"I'm looking to make this as short as possible."