Friday 23 December 2016 14:45, UK
Sunderland midfielder Jan Kirchhoff has been ruled out for 12 weeks after having an operation on his knee.
The 26-year-old German suffered the tear in his cartilage in the second half of the defeat to Chelsea last week.
He had an operation on the meniscus in his knee and is not expected to play until the end of March.
Kirchhoff was making only his third appearance of the season, after two months out with a hamstring injury.
He is the fifth Sunderland midfielder ruled out through injury with Lee Cattermole, Lynden Gooch, Paddy McNair and Duncan Watmore also sidelined.
David Moyes' side are bottom of the Premier League, four points from safety, and face Watford on Saturday.
The Black Cats have Didier Ndong available after serving a one-match suspension while Victor Anichebe and Steven Pienaar are set to have fitness tests after missing the 1-0 defeat to the Blues.