Adam Murray will see a specialist on Friday about his troublesome back.
The midfielder hasn’t played for a month, since the Tamworth game on January 16.
Manager Chris Wilder confirmed: “Muzzer goes to see a specialist on Friday, then we’ll determine where that goes.
“Obviously we’ve got to look after the long-term future, and back problems are not straightforward things.
“We’ll take a view of it when we get the specialist’s report.”
United’s central playmaker, who is so crafty at unlocking opposing defences, has been missed at times in recent weeks.
“You always want your best players and a fully-fit squad,” Wilder said.
“But that’s football. Stevenage have lost players, and York have lost players.
“These things happen, you just get on with it.”
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