The injury occurred during Monday's 4-0 loss to the Bruins in Boston. This adds to the injury setbacks Ennis has suffered in the last couple of years. He also missed a majority of the second half of last season due to concussion problems.
The 27-year-old has been a key producer on a struggling Sabres team, as he has 20 or more goals in three of his eight seasons in Buffalo. So far this season, he has a goal and an assist in 12 games played. Ennis joins Jack Eichel and Zach Bogosian on the Sabres' injury list. Eichel will miss another few weeks with a sprained ankle, while Bogosian is out with a sprained knee.