Craig Gordon could miss Sunderland's clash with Manchester United on Saturday.
The Scotland goalkeeper made his return from injury last week in Sunderland's 4-1 loss to Bolton at the Stadium of Light, but may be back on the sideline this weekend.
Black Cats manager Roy Keane said: "Craig trained for two or three days before the (Bolton) game and was keen to play, but he was obviously feeling the effects after the game.
"We took that gamble with him and if there is a reaction now to the injury, it will be a hammer blow."
Meanwhile, Anton Ferdinand could return to the starting line-up and face his brother Rio, who plays for United, after being left out for the Bolton match.
"Anton was fit, but so were other lads who were left out against Bolton," said Keane. "When you're losing games you try different things. Anton has a good chance of being involved at United."
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