In the second-half of the second leg tie at Fratton Park, O’Nien and Portsmouth defender Tom Naylor tussled on the sideline before the Black Cats full-back was forced over the edge of the advertising hoardings.

As he tried to get up, O’Nien appeared to be struck on numerous occasions by a member of the crowd.

“I went over the board and he had a few digs at me, but that’s football and it’s fine,” he told Sky Sports after Sunderland booked their place at Wembley.

“Police asked if I wanted to press charges, but that’s just football. When the whistle goes it’s just two teams going at it and two crowds going at it – that’s just part of it.

“There was a little bit of contact, but it was what it was. He didn’t hurt me in the end. I think he got arrested in the end, but he can have that one.”

Jack Ross, the Sunderland manager, said: “I asked the fourth official and he said I think a supporter had swung an arm
at him, which isn’t great.

“I wouldn’t make too big a deal of it, not because we won the tie but simply because I enjoy coming here. I think it’s a proper football ground, really good fan base.

“One idiot shouldn’t spoil it or tarnish that fan group.