Former England defender Ugo Ehiogu has died aged 44.
Ehiogu, who was the club's under-23s coach, collapsed at Tottenham's training centre on Thursday after suffering a cardiac arrest.
Tottenham announced his death this morning, saying in a statement: "It is with immense sadness that we announce the passing of Ugo Ehiogu."
Ehiogu, who played for Aston Villa and Middlesbrough and was capped by England on four occasions, joined Spurs as a coach in 2014.
Spurs' head of coaching and player development, John McDermott, said: "Words cannot express the sadness that we all feel at the club. Ugo's immense presence will be irreplaceable.
"Our heartfelt sympathies go out to his wife Gemma and his family."
Spurs also added their thanks to the North Middlesex University Hospital, Royal Brompton Hospital and Harefield Hospital.
Ehiogu began his career as a trainee at West Brom before he was taken to Villa by Ron Atkinson in 1991. He went on to feature in more than 300 matches for Villa and played in their FA Cup final defeat against Chelsea in 2000.
Ehiogu joined Middlesbrough for a then club-record B£8million fee later that year, and in 2001 he scored his only goal for England in Sven Goran-Eriksson's first game in charge, a 3-0 friendly victory against Spain.
Knee injuries plagued the final years of Ehiogu's career at the Riverside Stadium.
He joined Leeds on loan in 2006, and also had short spells with Rangers and Sheffield United before he retired from football in 2009.
The Football Association tweeted it was "devastated to hear the news" and further tributes from the governing body were expected, with England manager Gareth Southgate having played with Ehiogu for both Villa and Boro.
Villa released a statement expressing their sadness and added that there would be a minute's applause ahead of their derby with Birmingham on Sunday, with the teams wearing black armbands.
Lee Hendrie played with Ehiogu at Villa Park and with Sheffield United and told Sky Sports: "This is an absolute shock, to think this could happen to a man of his fitness and age. It is devastating, crazy.
"He was such a character, bubbly and would help anyone. He was a great guy to have around and never had problems with anyone. He was a gentle giant."
Boro said they were "deeply saddened to learn of the tragic passing" and Mark Schwarzer, who played with Ehiogu at the Riverside, told BBC Radio 5 Live: "He loved the game and he was really respected at Tottenham. It was a pleasure to play with him."
Striker Shayon Harrison, currently on loan at Yeovil from Tottenham, played under Ehiogu in his under-23 side.
"One of the most genuine and caring people I've ever met," he wrote on Twitter.
"An honour to have been taught by you, not only as a player but as a person."