Paetsch will miss "a pretty good period of time," coach Lindy Ruff said Thursday, a day after Paetsch was leveled by a vicious elbow from Pittsburgh's Georges Laraque during Buffalo's 7-3 loss Wednesday night.
Paetsch had just passed the puck from deep in his own zone early in the second period when Laraque skated by and hit him with a raised elbow. Paetsch lay face-first on the ice for several minutes before getting to his knees. He was assisted to the Sabres' dressing room.
Laraque drew a five-minute penalty, was ejected from the game, and received a three-game suspension from the NHL on Thursday.
In his second full season with Buffalo, Paetsch has a goal and seven assists in 54 games, but had gained additional ice time since the team traded All-Star Brian Campbell to San Jose last month.
The Sabres, 1-4-2 in their past seven games, are stuck in ninth place in the Eastern Conference, four points behind Philadelphia, which holds the final playoff spot. Buffalo has 11 games remaining, starting with a home game against Carolina on Friday.
Without Paetsch, the Sabres are down to five defensemen, including untested rookies Andrej Sekera and Mike Weber, after veterans Jaroslav Spacek (bruised ribs) and Dmitri Kalinin (shoulder) were hurt Monday.
Kalinin is expected to return within two weeks, but Spacek could miss the rest of the regular season.
Spacek told The Associated Press on Thursday he has a severe bruise in the middle of his chest and couldn't provide a timetable for his return because rest is the only rehabilitation for such an injury.
Ruff said the team has not determined whether to stay with five defensemen or call up a player from the minors. He's also toyed with the possibility of shifting play-making forward Jason Pominville to fill in at defense, although that will depend on whether Tim Connolly can play.
Connolly has been in and out of the lineup for the past two months, nagged by bone spurs in his hip, and was held out against Pittsburgh.