Tuch, a forward, was placed on injured reserve. He did not play the final 7:39 of the third period but remained on the bench until the end of a 3-1 win at the Florida Panthers on Friday.
Sabres general manager Kevyn Adams anticipates Tuch will be back before the end of the regular season.
"Where this is tricky is there's a range here," Adams said. "It's the longer side of week to week … but we're hopeful it will be on the shorter side."
Tuch, who played the first 57 games this season, is tied with Dahlin for second on the Sabres with 62 points (28 goals, 34 assists). He's skated the bulk of the season on a line with Tage Thompson and Jeff Skinner.
Jack Quinn took Tuch's place at right wing against the Washington Capitals on Sunday. He had two assists in a 7-4 victory at KeyBank Center in Buffalo.
"He's having a great season. He's playing in every situation, so you don't just replace that type of player, that type of role," Adams said. "But we believe internally in what we have in the locker room, and it's opportunity for guys to kind of step in, play a bigger role."
Dahlin, who has 14 goals and 48 assists in 56 games, did not play in the win Sunday. Adams said the injury is something that has been nagging the defenseman for a little while.
Kale Clague skated the first defense pair with Mattias Samuelsson.
"I don't want to say dealing with, but something that's kind of been going on with him for a little while and he's been battling through but just had gotten to a point where he has to get a day or two here and then we'll reevaluate," Adams said. "But he's more on the day to day side."
Buffalo (31-23-4) holds the second wild card into the Stanley Cup Playoffs from the Eastern Conference.
Forward Vinnie Hinostroza was recalled from Rochester of the American Hockey League.
