David Moyes is sweating on the fitness of Jermain Defoe ahead of Tuesday night's crunch match away to Leicester City.
The Sunderland and England striker went down in pain in the second half of the 1-0 defeat to Watford at the weekend after taking a knock to his right leg.
The England striker looked uncomfortable for several minutes after the challenge but did complete the game and showed no ill effects as the game wore on.
Sunderland boss David Moyes today confirmed he did not train with the rest of the first team squad yesterday ahead of Tuesday night's Premier League match.
Speaking at his pre-match press conference, Moyes said: "Jermain didn't train yesterday. I can't give you any more of an update than that."
A club spokesman then confirmed the players are yet to train today and the 14-goal top scorer could be involved in today's session.
Sunderland are bottom of the league, eight points from safety with just nine games to go.