Sunderland boss David Moyes has labelled the injury to Jan Kirchhoff as a 'massive blow' for the club.
The midfielder has been ruled out for up to eight weeks after appearing to damage his hamstring whilst falling awkwardly in the draw with West Brom at the weekend and the club have confirmed he faces a prolonged spell on the sidelines.
Moyes says it is a massive blow to the club to lose someone of such ability from their side.
He told the Echo: "Not to have him, Steven Pienaar and Adnan Januzaj is massive, because they help us play better and we are short in that area. They are big, big misses to this club.
“If we lose Kirch and we lose Catts, we lose a little bit of the steel and a little bit of the boys who have been here before while we’re looking to build a new team.”