The Wrexham striker came on as a substitute for the second half of the Championship clash at Bramall Lane and although he required treatment when he sustained the injury, was able to complete the match.

However, Reds boss Parkinson had bad news to report ahead of tomorrow's showdown with leaders Middlesbrough at The Racecourse.

"Unfortunately for us, Sam picked up a knee injury in the game and it looks like he's going to face a significant period on the sidelines," he said.

"He came off against Sheffield and then went back on, carried on, and then his knee swelled up significantly the next day.

"It's a blow for us with Sam. He sees a specialist this afternoon at 4pm and we'll know more then.

"We'll just see how the appointment goes but the initial thoughts are that he could need surgery

"But as I said to the lads, injuries are injuries. We've got to find a way in games like we did against Preston to come out on top and be effective as a team."