Sunderland boss David Moyes has been dealt a massive injury blow with the news that Jan Kirchhoff has suffered a cartilage tear.
The former Bayern Munich man, who was this week linked with a move back to the Bundesliga with Hamburg, has been ruled out of tomorrow's clash with Watford at the Stadium of Light.
And, although no timeframe has been put on his return, it is likely that Kirchhoff will miss a considerable amount of time with the knee problem.
Confirming the news at his pre-match press conference, Moyes said: " "Jan Kirchhoff is out.
"He has suffered a cartilage tear in Wednesday's match.
"As yet though there is no time frame."
Kirchhoff operated in a two man central midfield pairing against Chelsea in midweek, alongside Jason Denayer. And it is likely that Didier Ndong, who missed the Blues match due to suspension, will come straight back into the side in place of Kirchhoff.
Elsewhere on the injury front, Moyes says he will make a late decision on three more of his injured troops.
He said: "Late decisions will be made tomorrow over the fitness of Victor Anichebe, Steven Pienaar and Javier Manquillo."