Oxford United keeper Ryan Clarke has been ruled out for 10 weeks and could be out for the rest of the season after manager Chris Wilder revealed he needs double shoulder surgery.
Player-coach Wayne Brown, 35, started Saturday's 2-1 win at Bradford but the U's could look to make a loan signing.
"Ryan has had a problem that has been going on now for six to eight weeks," Wilder told BBC Radio Oxford.
"He's not trained as much as he should have and I've just seen a dip in him."
The dramatic win at Bradford sees Oxford just two points off the play offs.
And the U's boss admits it was a tough decision to force his 30-year-old first-choice keeper to have an operation.
"It's not his fault as he is obviously carrying it and the boy to be fair was brave enough to want to bat through this period," added Wilder.
"But I just made a decision in the week (after the Johnstone's Paint Trophy penalty shoot out defeat by Southend).
"I just didn't think it was fair on him and I think there have been a couple of soft goals and I do believe he would have saved all three penalties that went through him on Tuesday if he was fit.
"I think he was relieved. He knows the situation, let's see how (Wayne) Browny does, and we've got young Max Crocombe who we could also throw in."