"I had a scan to assess why I felt unwell and had to leave the game at Ipswich early, and the doctors discovered a small, operable tumour that caused an affliction on the left side of my face," the 73-year-old said.

"On Wednesday I will have an operation to remove the tumour and, as surgeons tell me the rest of my body is clean, I should be able to make a full recovery."

In January this year, he was appointed international football consultant to the Republic of Ireland alongside national team coach Steve Staunton.

Ennobled by Queen Elizabeth II for services to football in 2002, Sir Bobby said the tumour is in a position where it can be easily removed and is the size of a grape, "which indicated they have caught it early".

"Apart from the funny turn at the match I have felt great, so it's a bit annoying that I have to go into hospital again," he added.

Sir Bobby has successfully fought cancer three times: he had a golf ball-sized tumour removed from his lung in May, while in 1995, he was discovered to have a rare form of skin cancer behind an eye.

Treatment for that involved complex surgery which left him needing a rubber plug in his mouth; three years before that he overcame bowel cancer.