O’Connell was withdrawn from United’s Yorkshire derby against Leeds - which Marcelo Bielsa’s side won 1-0 following Patrick Bamford’s 88th minute header - after an issue which has troubled him since the end of last season flared-up again in the week.
Acknowledging the situation “needed sorting”, Wilder explained how O’Connell has been playing through the pain barrier for the past few months, having also experienced problems towards the end of last term.
“As a young player, he’s had a couple of issues,” Wilder said. “Jack had an injury last year, just after lockdown, and then got back playing again towards the end of last season.
“We got him going again in pre-season, but you can see where he’s playing at, that he’s below the levels where he’s usually at, the levels he usually hits and where he needs to be.
“He’s been having discomfort again and we’re wrapping him up in cotton wool. But, long-term, it’s not good for him to carry on. We’re in conversations with the medical people, the doctor here and the specialist down in London.”
United were without two of their first choice centre-halves for the meeting with Leeds, after John Egan missed the fixture through suspension following his controversial red card at Aston Villa six days earlier.
“For Jack to be potentially out for the rest of the season, it’s a big blow for us and a very cruel one for him,” Wilder acknowledged. “Our back three are hugely influential for us and Jack has been with us right the way through, all the way from the days in League One.”