TONY MOWBRAY admitted Luke O’Nien’s red card in Sunderland’s 3-1 defeat to Swansea City was merited, and conceded that the defender might have become caught up in the febrile atmosphere that was being generated at the Stadium of Light.

O’Nien received a straight red card from referee Keith Stroud after he flew into a challenge with Swansea midfielder Ollie Cooper in the 18th minute of this afternoon’s game.

The Black Cats centre-half failed to make contact with the ball as he clattered into Cooper, with his dismissal meaning his side were forced to play for more than 70 minutes with ten men.

Sunderland’s players felt they should have had a penalty moments before O’Nien was dismissed, with Amad Diallo appearing to have been clipped as he tumbled close to the byline, but Mowbray feels any sense of injustice cannot excuse the challenge that led to the red card.

“I haven't watched the incidents back, but my instant reaction to the red was that with the ferocity of the tackle, and the fact that he's missed the ball, I think the ferocity of the challenge is what has got him the red card,” said Mowbray.

“It's modern-day football and you have to accept it. I think the speed of the challenge is what gets the red card. It was obviously a long afternoon for us after that against a team that plays possession football, it's difficult enough to play with 11 against 11.”

O’Nien appeared to react to the crowd’s fury at the referee’s decision not to award a spot-kick for the challenge on Amad, with Mowbray admitting that a much cooler head was required.

O’Nien apologised to his team-mates in the dressing room after the game, and while Mowbray does not feel the need to personally admonish him, he is confident the defender will learn from his error.

“Luke’s a very level-headed kid,” said Mowbray. “Yet I think it’s quite natural to get wrapped up in the game. It felt as if for a spell, the supporters could be our 11th man and make it an even game as such. The crowd can play such an important part, but maybe they overwound Luke O’Nien up a bit.

“My job today was to try to make sure these players played with intensity against this team that were coming to try to dominate the ball, and I thought we did it brilliantly well for however long it was before the sending off.

“Luke was stepping out from a central-defensive position into a midfield area, where their number nine had dropped down, and we’d talked about how the centre-halves had to drop in with them because they play in the spaces.

“It was just an overly-aggressive challenge. I’ve told him that. There was no need for that intent, yet you can imagine if he had made real clean contact and the ball had flown 50 yards up the field, the crowd would have roared and it would have kept the momentum going. Ultimately, though, on the back of that decision, the game swung pretty dramatically.”