Housley said Eichel will miss four to six weeks, putting the player in position to return in the final weeks of the season, even though Buffalo might not have much to play for at that point. The Sabres are last in the Eastern Conference standings and sit 19 points out of playoff contention with 27 games left.
"We've still got a lot to prove this season still," Housley said Sunday before Buffalo's home game against Colorado and a day after Eichel was hurt in a 4-2 win at Boston. "We've still got a lot of games at home here left. We want to win these games not only for our fans but to build on things."
Eichel was hurt during the first period while attempting to play the puck behind the Bruins net. He was checked from behind by Boston's Matt Grzelcyk and fell awkwardly into the boards.
Eichel leads Buffalo with 22 goals and 53 points in 55 games in his third season since being selected with the No. 2 pick in the 2015 draft. Eichel became the franchise's highest-paid player when he signed an eight-year, $80 million contract extension in October. The contract kicks in next season.
Eichel missed the first 21 games of the 2016-17 season with a sprained left ankle.
The injury depletes the offensively challenged Sabres of their most consistent threat, whose production has heated up over the past two months. Eichel has 15 goals and 34 points in his past 30 games and was part of a power-play unit that has converted 13 of its past 39 chances.
"Yeah, it's difficult, especially the way he's been playing the last two-and-a-half months," Housley said. "He's really come into his own."
Buffalo began the day tied with Arizona for last in the NHL with 128 goals and last in the NHL with 77 goals scored in five-on-five situations.
The Sabres called up forward Nicholas Baptiste from Rochester, their American Hockey League affiliate.