Coach Lindy Ruff provided the update on Thursday, a day after Weber was hurt in a 5-3 loss to New Jersey. It was only Weber's third game after spending much of the season as a healthy scratch.
With Weber out, the Sabres called up defenseman T.J. Brennan from the minors. Buffalo's 2007 second-round draft pick, Brennan has an opportunity to make his NHL debut on Friday, when the Sabres travel to play Carolina. He has two goals and six points in 16 games with AHL Rochester this season.