Former Liverpool and Everton defender Gary Ablett has died aged 46 after a long battle against cancer, the League Managers Association confirmed.
Ablett, who had a season as Stockport manager in 2009-10, lost his 16-month fight against non-Hodgkin's lymphoma on Sunday night.
"On behalf of Gary Ablett's family the LMA has today confirmed that Gary passed away peacefully last night following a hard fought 16-month battle against non-Hodgkin's lymphoma," said an LMA statement.
"Respected throughout the game by players, coaches and managers alike Gary will be sadly missed.
"The LMA's thoughts and condolences are with Gary's wife Jacqueline and children."
Ablett, who also made over 100 appearances for Birmingham, took up a coaching role with Ipswich in July 2010 but was taken ill while at the club's training ground and was diagnosed with non-Hodgkin's lymphoma.
"Liverpool Football Club were today saddened to learn of the death of former player Gary Ablett," said a statement from the Reds. "The staff of Liverpool FC would like to send our condolences to the family and friends of Gary."
An Everton statement read: "Everyone at Everton was saddened to learn of the death of Gary Ablett. The thoughts of everyone at Everton are with Gary's family and friends at this tragic time."
Former Liverpool manager Roy Evans told Sky Sports News: "It's a big shock. Obviously we know Gary's been ill for a while. It's a really sad day."
Recalling Ablett as a player, Evans added: "He was good at everything he did as a player.
"He went into coaching and stamped his personality onto that and was doing a very good job, certainly at youth level. I remember he had bit of a difficult first spell at Stockport, but overall he's had a great career in football, he's a big loss to the sport.
"He made a big contribution to the game."
David Fairclough, who played for Liverpool between 1974 and 1983, added: "He was a lovely lad, he always conducted himself in the right way. He was great with people, always personable. What always came through with Gary was his attitude was just always very, very right."
Former Reds striker Michael Owen wrote on Twitter: "So sad to hear the news that Gary Ablett has passed away today aged 46. He played for some great clubs and had a career to be proud of. RIP"
Birmingham have announced a minute's silence will be observed before their Championship match at Peterborough today with another held at St Andrew's on Saturday prior to their FA Cup third round tie with Wolves.
"The thoughts of everyone connected with Birmingham City Football Club are with the friends and family of Gary Ablett," said a Blues statement.
"Our deepest sympathies and condolences go out to Gary's wife Jacqueline and his children and everyone else that knew him."
Ipswich's players will wear black armbands for this afternoon's visit of Nottingham Forest and Ablett will be honoured with a minute's .
"It's desperately sad news," Town chief executive Simon Clegg told the club's official website.
"I stayed in touch with Gary as he battled his illness over 18 months, which he did with bravery and dignity and our thoughts go out to his wife Jacqueline and their children at this very difficult time."