Blues legend George Burley is undergoing treatment for cancer, the club has announced.
Right-back Burley was a key man in Sir Bobby Robson’s team in the 1970s and early 1980s before going on to manage the Blues between 1994 and 2002, taking them to promotion at Wembley in 2000 and then to fifth in the Premier League and back into Europe the following season.
The 68-year-old, who also played for and managed Scotland, has been involved in more Town matches than anyone else, 500 as a player and 413 as a manager.
"After feeling unwell earlier this year, I have recently received a diagnosis and I am taking positive action to fight the disease,” Burley said.
"It has been a difficult time, but I am feeling much brighter now. In fact, I am able to get to matches at Portman Road and I am enjoying watching the team playing back in the Premier League.”
He added: "We are grateful to the club for the support they have shown me and my family and I would ask that everyone is respectful of our privacy at this time.”
Current Blues boss Kieran McKenna said: "This club has had some brilliant managers and George is right up there as one of the very best.
"It has been a pleasure to get to know George since I arrived at Ipswich. He is a positive and optimistic character, and I know he will also take that attitude into the battle he now faces. We are all right behind him.”
Chairman and CEO Mark Ashton added: "Our thoughts are with George, his wife Jill and their family. It’s always great to see him here in the directors’ box on a matchday and we will do everything we can to support one of our all-time greats, uniquely as both player and manager.”
In addition to his time with Town, Burley also played for Sunderland, Gillingham, Motherwell, Ayr United, Falkirk and Colchester United, having won 11 full Scotland caps while with the Blues.
He began his management career while still a player at Ayr United, then had a spell at Motherwell as a player-coach before taking charge at Colchester in the summer of 1994, an impressive start at Layer Road leading to his return to Portman Road.
He later had spells in charge at Derby, Hearts, Southampton, Scotland, Crystal Palace and in Cyprus with Apollon Limassol.
A new book, All to Play For, celebrating Burley’s Town management career is set for publication in November.