Lewis Guy will make his debut for Oxford United on Wednesday – but Chris Wilder would not be drawn on whether he would start or come off the bench.

The U’s manager snapped up the 26-year-old striker on a one-month loan from MK Dons after learning that Tom Craddock needs an operation on his knee injury.

Guy, who will wear No 27, played against United in pre-season and will be involved in the Carling Cup first-round match against Cardiff at the Kassam Stadium.

Wilder will decide on how many, if any, changes he makes from Saturday’s 1-0 defeat at Rotherham – but Guy will feature in some capacity.

“He will definitely be involved,” Wilder said.

“I know a lot about him and went to watch him a few times while he was at Doncaster.

“He can plays in numerous positions in attack, is bright and lively and a good, intelligent footballer.

“We have a decision to make now as to whether we chuck him straight in or put him on the bench.”

Wilder is looking for his side to bounce back from Saturday’s defeat – in which the manner of the loss more than anything hurt the U’s boss.

“We’ve got to do better,” he said.

“We were really disappointed because we didn’t produce to the standards we know we are capable of.

“But playing against a top Championship side like Cardiff is not going to be easy and we might have to be under the cosh a bit more, but we’ll have a real go at it.

“If Cardiff go through, like they are expecting to, we must make sure that they have been given a tough task to get there.”

Cardiff will be forced into several changes from the side that beat West Ham on Sunday because of international call-ups.

Nine players are on duty with their country, including first-choice strikers Kenny Miller and Robert Earnshaw.

Manager Malky Mackay has not yet finalised his squad, with several of his bench set to be members of the club’s youth system, although he has said that Rudy Gestede will lead the attack.

The Bluebirds squad has been decimated by the loss of Miller, Earnshaw, Don Cowie, Kevin McNaughton, Darcy Blake, Joe Mason, Dekel Keinan, Aron Gunnarsson and Filip Kiss to their respective nations.

TONIGHT’S SQUADS Oxford Utd: from Clarke, Batt, Whing, Duberry, Wright, Tonkin, Heslop, Hall, Payne, Leven, Constable, Smalley, Guy, Pittman, Potter, Craddock, Clist, James, Brown, Davis, McLaren, Woodley.

Cardiff: from Heaton, Marshall, Taylor, Hudson, Gyepes, Naylor, Gerrard, Naylor, Whittingham, Conway, Gestede, Quinn, Parkin, Jarvis, Farah, Evans.

* The match will go to extra time and penalties if necessary.

* Oxford United fans could see a new physio against Cardiff.

Jon Brown has left the club, and should any U’s players need treatment, Max Martini, who has been doing the job for the youth team, will be called upon.

However, we understand United will have a permanent replacement for Brown in place shortly.