Former Tottenham captain Gary Mabbutt is set to undergo heart surgery.
Spurs say the 55-year-old was taken to hospital on Monday morning after experiencing chest pains and breathing problems.
"Gary Mabbutt was admitted to hospital this morning where he will undergo heart surgery later after suffering chest pains and breathlessness," Spurs announced on their Twitter account.
"Everyone at the club wishes our legendary former captain a speedy recovery. Get well soon, Mabbsy!"
Mabbutt spent 16 years at Tottenham after joining from Bristol Rovers in 1982.
The defender was part of the Spurs side which won the UEFA Cup in 1984 and captained them to victory in the FA Cup final against Nottingham Forest in 1991.
A hugely popular figure at White Hart Lane, he played in 477 league matches for the club to lie second in their all-time appearances list. He also played 16 times for England.
In 2013 Mabbutt, who was diagnosed with Type 1 diabetes as a teenager, needed an operation to replace the main artery in his left leg.
Two years later he told BBC Radio 5 Live: "I can no longer do any sport or go running, and my life is now a lot more sedentary.
"It is frustrating that I cannot kick a ball ever again, but I still have my leg, which is the most important thing."