Sheffield United defender Jack O'Connell's season could already be over due to a knee injuruy.

He was left out of the Blades' Yorkshire Derby with Leeds United on Sunday and manager Chris Wilder revealed the centre-back will be out for an extended period with his procedure set to take place on Wednesday.

O'Connell has suffered with the knee issue for around a year and the 26-year-old missed a cluster of matches in Sheffield United's promotion campaign and just after the coronavirus hiatus earlier this year with the injury.

Speaking before the Bramall Lane encounter, Wilder said: "It's really bad news from our point of view. Jack's possibly going to be out for the rest of the season.

"He needs an operation on a knee he injured last year. He's tried to come back, we've had it scanned and he was a big part of the back three who did outstandingly well last season.

"We've got to adjust pretty quickly but it's just more bad news for Jack really because he established himself well in the Premier League last year.

"He had a fabulous season and for him to be out for the rest of the season is a huge blow for him and us."