Revealed: When Sheffield United are likely to decide if they will try and sign Everton's Mo Besic

Besic, who scored his first goal for the club during Saturday’s FA Cup tie at Millwall, is scheduled to spend the rest of the season with Wilder’s squad after arriving from Everton in August.

A peripheral figure at the beginning of the campaign, Besic’s influence has grown in recent weeks, prompting suggestions United should consider signing him now rather than wait until the Bosnia and Herzegovina international enters the final year of his contract at Goodison Park.

But after outlining plans to sign at least one new player before the transfer window closes on Friday, Wilder explained the terms of United’s arrangement with Besic means he is likely to evaluate the situation following May’s Premier League fixture at Southampton.

“Yes, there’s no break in his contract in this window,” the United manager said. “It’s only if someone wants to come in to sign him permanently.”

Besic, aged 27, was among six players to feature in Wilder’s first choice eleven at The Den after also starting against Manchester City four days earlier.

“I believe it was right that we made a couple of changes,” Wilder continued. “Enda (Stevens) and George (Baldock) have been fabulous in the distances they have covered.

“Lunny (John Lundstram) has put in a lot of graft and covered a lot of miles, and so has Flecky (John Fleck).

“It’s comforting when you put the other boys in and they produce performances.”

Besic set United on course for the fifth round when, following an excellent piece of build-up play by captain Billy Sharp, he produced an even better piece of skill to beat Millwall’s Bartosz Bialkowski from long-range.

Wilder’s side, who return to London when they face Crystal Palace this weekend, sealed their progress when Oliver Norwood drilled a low shot past the Pole and into the back of the net.

Revealing Besic was about to be substituted when he broke the deadlock, Wilder said: “I actually didn’t think it was one of Mo’s better performances.

“But then he scored and he came alive, which was great.

“He had to pull something out of the bag, as the board was up and a change was in the offing.

“That was John. He (Besic) might have have a little peek over and thought ‘I might have to do something here to keep on the pitch.’

“His performance, overall though, was good. It was a great goal and he’s a popular boy.”