Tottenham boss Harry Redknapp admits he feared the worst after seeing Fabrice Muamba being treated on the pitch on Saturday.
Bolton's Muamba collapsed at White Hart Lane shortly before half-time in their FA Cup quarter-final clash.
Medics raced to his aid after he suffered what later emerged as a cardiac arrest.
"When they were pumping his heart, we realised just how desperate it was. I feared the worst," he told Sky Sports.
"None of us could believe what had happened. Everyone was shocked.
"I just remember him laying on the floor and my first thought was that someone elbowed him off the ball.
"Then we saw the pumping of his chest, but the medical people were fantastic, then the heart people came out of the crowd, specialists who were at the game, they came on the pitch and leant their expertise.
"They were all amazing and the crowd were fantastic, so respectful and the referee handled it so well, he was top drawer and a lot of credit to him too."
Redknapp feared he was witnessing a repeat of what happened to his former player Marc Vivien Foe, who collapsed and died during a Confederations Cup match with Cameroon in 2003.
"Marc played for me at West Ham. That was horrendous, the lucky thing for Fabrice was that it was at a Prem ground," he said,
"If it had been a Sunday morning footballer or non-league, I do not think he would have pulled through.
"It was obviously a problem that was there so it was lucky it happened where it did as the medical people were fantastic."
Meanwhile, Redknapp confirmed that Tottenham will be playing against Stoke on Wednesday - although the Potters did offer to postpone the match.
"He [Tony Pulis] said 'look Harry if the players are not ready to play, whatever you want Stoke will back you' but we have to carry on and play on," added Redknapp.
"I can understand Bolton not playing and even the weekend, their players are so close to Fabrice so that must be an unbelievable situation and they must get on with it and they will be ready by Wednesday."