Sunderland manager David Moyes has revealed that Jan Kirchhoff has suffered a setback in his recovery from a knee injury.
The 26-year-old has not featured for the struggling Black Cats since December, but had been nearing a return and played an hour in a recent Under-23 match against Manchester United.
However, the midfielder's knee reacted badly to the run-out and Moyes is now expecting to be without the German for a further four weeks.
"Jan has unfortunately had a recurrence of his knee problem and it looks like it is going to keep him out for a minimum of four weeks," he told reporters.
"I don't think there is any damage, but it is going to take longer than we thought to heal."
Kirchhoff has been limited to just seven Premier League appearances this season having also struggled with a hamstring injury earlier in the campaign.
