Concerns over the potential fee to sign Sander Berge stem from his recent injury, not his ability as a footballer, with several sides currently interested in signing the midfielder, Football League World can reveal.

Liverpool, Aston Villa, Arsenal and Napoli are all interested in the Sheffield United midfielder and it looks quite possible that he could be leaving the Blades during this current transfer window.

The Blades want £35m for the player, meanwhile, and think that is a fair representation of the ability he possesses, though some clubs have reservations after he needed surgery on a tendon last season.

Football League World understands that potential buyers are seeking medical assurances over the player, with it being big money that they'd potentially be parting with if they did sanction a deal to sign him up.

Berge picked up the injury back in December after blocking a ball during a defeat at the hands of Manchester United.

A tendon was pulled off the bone and surgery was the only course of action to solve the issue, with him ruled out for a significant period after that.

It makes sense, then, that potential buyers want to know he's not going to suffer recurrences but, of course, you'd need a crystal ball to be completely sure in that regard.