Celtic's Alan Stubbs expects to leave hospital by the end of the week after having an operation on an un-named condition yesterday, which he believes has been a success.

The 27-year-old central defender was in upbeat mood following surgery at 8.30 a.m. in a private hospital.

"I had an operation earlier today, and it appears to have been a success," he said in a short statement released through the club.

"I feel comfortable following the operation and would hope to leave hospital by the end of the week.

"I would like to thank everyone for their kind words of support. I would especially like to thank the doctors and nurses who are looking after me so well."

It is believed that Stubbs' parents Doreen and Ronnie have travelled up from their home on Merseyside to be with their son.

Stubbs' illness, which is understood to be cancer-related, came to light during a random drug test after the Scottish Cup final against Rangers in May, which Celtic lost 1-0.

The former Bolton player has two years of a five-year contract to run, and Celtic have vowed to do everything in their power to help him.

Stubbs joined the Glasgow club in 1996 in a £3.5-million deal secured by former manager Tommy Burns.

John McGinlay, a former team-mate of Stubbs at Bolton, was delighted to hear the operation had apparently been a success.

"It is good to hear the big fellow being so positive," said the former Scotland striker.