Jos Luhukay has confirmed Sheffield Wednesday midfielder Kieran Lee has suffered a setback in his bid to return from a long-term injury.
The 30-year-old has not played - due to a hip injury - since defeat at Norwich City in December last year.
He had spent eight months on the sidelines, but his long-awaited return for the club’s Under-23s lasted just 15 minutes.
“Kieran played for the first time last Monday for our Under-23s and played only 15 minutes before he felt something at the back of his knee,” said Owls manager Luhukay.
“He's had a scan. We must have patience. He will not be available to us in the next weeks.
“He was coming closer to the team and was going in a good direction. He's a positive person with a very good character.
“He is now very disappointed and this is normal. It had taken him a lot of time to come back to where he was last week.
“He has been out now for almost a year. The medical team are supporting him every day. Everyone at the club will try to help him so he can come back again.”
Striker Gary Hooper - another long-term absentee - featured in the same Under-23 game, and is due for another run-out next week.
Luhukay said: “It takes time. Gary was out for eight months and then played for 45 minutes for the Under-23s last Monday.
“Next Monday he will play for them for 65/70 minutes. The time when he can play 90 minutes for the first team is a little bit in the future. We have to have patience.”
Luhukay also gave updates on Wednesday’s other injured players, ahead of Saturday's visit of Stoke City in the Championship.
Striker Sam Winnall has a calf issue, as he battles back from a serious knee injury, and has spent the last fortnight out of first-team training.
While midfielder Sam Hutchinson is due to return to training next week, after treatment in Spain on a groin issue.