Sunderland manager Simon Grayson says Tyias Browning has suffered a setback in his recovery from injury and is likely to miss the next couple of matches for the Championship side.
Former England Under-20 international Browning joined Sunderland on a season-long loan from Everton in the summer and has been a regular first-team fixture, making nine Championship appearances.
However, the 23-year-old centre-back has not featured in the last two matches due to a hamstring complaint and it appears he will be on the sidelines for a while longer.
The defender was expected to return to action at home to Bristol City on Saturday, but Grayson has now revealed the he continues to be hampered by the injury.
He said: “Tyias had a little setback on Thursday with his hamstring so we’ll see where he’s going to be for the next couple of games.”
The Black Cats are currently in 23rd position, winning just one of their 13 matches and conceding 25 goals.
Victory should have been picked up last time out but the north east outfit let a 3-1 lead away at Brentford, who are only above the bottom three by three points, slip and had to settle for a 3-3 draw instead.
Sunderland are 2.70 to pick up a second win of the season at home to Bristol City on Saturday.
The draw is priced at 3.40 while the visitors, who are flying high in seventh, are 2.60 favourites.