03/22/2012 09:11 EDT | Updated 05/22/2012 05:12 EDT

Muamba's manager 'astonished' at midfielder's improvement since on-field cardiac arrest

LONDON - Fabrice Muamba's manager at Premier League club Bolton says he is "astonished" at the England under-21 midfielder's improvement since suffering an on-field cardiac arrest on Saturday.

Muamba's heart stopped beating on its own for 78 minutes after he collapsed during an FA Cup match at Tottenham.

Owen Coyle says the player "is still in intensive care and in a serious condition" at London Chest Hospital, but that he has improved dramatically.

Bolton will return to action on Saturday against Blackburn, and Coyle says he will let players upset at witnessing Muamba's collapse sit out the Premier League game if they feel unready to play.

Coyle said Thursday that he "wouldn't ask anybody to play in these circumstances if they weren't in a position to do so."