England manager Gareth Southgate led the tributes on Friday to "gentle giant" Ugo Ehiogu after the sudden death of the former Aston Villa star at the age of 44.
Ehiogu collapsed on Thursday at Tottenham's training centre, where he worked as the club's under-23 coach, after suffering a cardiac arrest.
Southgate had a close bond with Ehiogu, having played alongside the centre-back with Villa, Middlesbrough and England.
Praising Ehiogu's personal and professional qualities, Southgate summed up the feelings of many within British football, which was shocked by the untimely departure of a man respected for his prowess on the pitch and his warm personality off it.
"I'm stunned and deeply saddened by Ugo's passing and clearly my initial thoughts are with his wife Gemma, his children and his family," Southgate said.
"I know that football will be grieving because he was so highly respected by everybody he worked with and losing him at such a young age is difficult to come to terms with.
"Most importantly, he was a gentleman and he is one of those characters that people would find it difficult to have anything bad to say about him.
"I probably played more games with Ugo than anybody else in my career and while in many ways he was a gentle giant away from football, he was a colossus on the pitch."
Ehiogu, capped four times by England, had been on Tottenham's coaching staff since 2014.
Tottenham's head of coaching and player development, John McDermott, said: "Words cannot express the shock and 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."
Ehiogu made over 300 appearances in a nine-year stay with Villa, helping them win the League Cup in 1994 and 1996.
He joined Middlesbrough in 2000, spending seven years there and winning the League Cup again in 2004.
Ehiogu also played for West Bromwich Albion, Leeds, Glasgow Rangers and Sheffield United before retiring in 2009.
Australia's Mark Schwarzer, who played with the centre-back at Middlesbrough, called him "the ultimate professional".
Former Republic of Ireland midfielder Andy Townsend, a Villa team-mate of Ehiogu's, added: "I'm absolutely shocked. I didn't expect to wake up to this news.
"He was a player that every team would like to have at the back.
"I remember the 3-0 win over Leeds (in the League Cup final). I looked at pictures at home this morning and Ugo is in them celebrating."