Murray was shown a straight red card for a foul on Jack Currie in the 72nd minute – just three minutes after substitute Christian Saydee had struck a spectacular equaliser.

And with the extra man, Oxford found a late winner through Kai Andrews to condemn bottom club Wigan to their seventh league defeat of the campaign.

Caldwell said: “It was not a red card. You get enough of an advantage playing at home, and Oxford are a good team, without getting extra help like that.

“We were poor first half, way off it in terms of aggression, hunger and desire.

“They came out really aggressively on the press and we made poor decisions when being pressed, and were just too passive.

“But we managed to get a handle on the game and I thought we would be going in at half-time level, so it was disappointing to concede just before the break.

“But we were good in the second half and when we got it back to 1-1, I thought we would get something from the game. And with 11 v 11, I think we would have got something here.”

Oxford had taken the lead on 44 minutes through centre-half Michal Helik, and they dominated the first half.

U’s head coach Aaron Ramsey said: “There was loads to like about that performance.

“I thought we were in complete control of the game and with their goal – from their first shot on target… those things happen sometimes.

“Yes, there are things that I think we can improve on. But I thought the way we responded to get the win, against 10 men as well which is often not easy because they settle into a low block, we showed great character again.

“I’m not sure I believe it was a red card, but we were on the wrong end of that last week.

“Kai Andrews had a fantastic game tonight – he was everywhere, creating attacks, getting into the box, getting on the end of things. He’s got that ability, and it’s really pleasing for him to get that goal tonight to cap it off.

“We need to take care of our home games so it was really pleasing that we got the win. We got into the final third really well today, perhaps we could have been a little more clinical in the final third and that’s a little bit to look at and try to improve on.

“It was great to see Aidomo Emakhu come on and look really sharp – he had a real impact when he came on. He’s a big player for us.”