Norman Whiteside now and in his Manchester United days

Belfast-born Whiteside, now 42 and living in Cheshire, said he had a procedure three months ago to correct his irregular heart rhythm.

Mr Whiteside's wife Denise played down suggestions it was a serious problem.

"He recovered on the day. You go in in the morning, come out on the afternoon, it is just an electrical imbalance of the heart. It's not a massive thing."

She added: "He's absolutely fine and healthy, and perfectly well right now."

It was the same procedure undergone by Tony Blair in October 2004.

The Shankill Road man made his first-team debut for Manchester United at the age of 16.

He later became the youngest player to appear in the World Cup finals.

Whiteside was an FA Cup winner, scoring the winning goal in the final in 1985.

He now works as a podiatrist for the Professional Footballers' Association.