Fabrice Muamba's manager at Premier League club Bolton is "astonished" at the midfielder's improvement since his on-field cardiac arrest.
Muamba's heart stopped beating on its own for 78 minutes after he collapsed during an FA Cup match at Tottenham on Saturday. Doctors worked on him during that time, administering 15 shocks from a defibrillator.
Owen Coyle said Thursday that the player is still seriously ill at London Chest Hospital, where he was taken after his collapse at White Hart Lane, but that he has improved dramatically.
"Where we are now from that moment on Saturday evening, we are astonished," Coyle said. "But within that, it is extremely important we don't get too ahead of ourselves because we have to remember that Fabrice is still in intensive care and in a serious condition.
"The level of support that he has had has been incredible. I've got to say that it has been humbling at times."
Bolton will return to action on Saturday against Blackburn, and Coyle will let players upset at witnessing Muamba's collapse sit out the Premier League game if needed.
"We have to go and play the match and do it to the best of our ability. Will it be difficult? Absolutely," Coyle said. "Some people are affected in different ways than others.
"I wouldn't ask anybody to play in these circumstances if they weren't in a position to do so. It will be a difficult game of football because all of our thoughts will remain with Fabrice."
Bolton's FA Cup quarterfinal at Tottenham has been rescheduled for Tuesday. Although the game was abandoned when Muamba collapsed just before halftime with the score 1-1, the match will be restarted.
Medics tried to revive Muamba for 48 minutes before he arrived at the east London hospital. Bolton team doctor Jonathan Tobin said it then took another 30 minutes, after 15 shocks from a defibrillator, before the player's heart started beating on its own again.
The cause of the cardiac arrest has not been discovered. Doctors said that Muamba had undergone a routine screening for heart defects in August. He was checked again Sunday, with the test producing a normal result.
It is too early to say if he can play professionally again.