OXFORD United boss Karl Robinson is targeting four signings in the January transfer window.

The U’s head coach revealed he wants to recruit two wingers and a centre back, but would not disclose the final position he is seeking to strengthen.

New rules which limit United’s squad to 22 players aged over 21 means there must be three departures if there are four new arrivals.

Joel Cooper’s return to Linfield on loan has freed up a place, but Robinson admitted he would have some tough decisions ahead.

He said: “It’ll sort of depend on the availability of some of the players we bring in.

“We’ll just have to wait and see.

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“We’re having some very interesting conversations with players outside of this football club that whet the appetite.

“Equally, if those fall flat on their face I could be on my hands and knees with a begging bowl to keep people motivated.”

United play twice before the window opens, with the Boxing Day clash at home to AFC Wimbledon followed by a trip to Plymouth Argyle next Tuesday.

Robinson is undecided about which U’s players may leave the club and maintained those at risk can still change his mind.

“There’s always time,” he said.

“A lot of it is down to some of their decisions, as well as my own.

“There’s one person that will have a big relevance on what we do, but that’s something we’ll keep to ourselves.”

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Robinson added: “The important thing is all of these players know they’ve got a future here.

“It’s solely in their hands.

“The one component that I don’t ever give them a percentage back on is their effort.

“The pride we have in the badge has to stand for nothing other than 100 per cent effort.

“If you fall short of that, you fall short of playing for the football club.”

One option could be leaving an existing player out of the registered squad for the second half of the season, like United did with Derick Osei for the first part of the campaign.

The squad size regulations have been brought in alongside the salary cap that limits Sky Bet League One clubs’ spending to £2.5million per season.

Robinson has voiced his opposition to the rules on many occasions, but knows he has to make the best of the situation.

He said: “This is what makes the ridiculous salary cap laughable.

“We can’t get around it right now, it’s something that we’ll learn to live with.

“Hopefully we can find a way that suits everybody.”