The London Chest Hospital have confirmed that Bolton's Fabrice Muamba suffered a cardiac arrest during the FA Cup clash with Tottenham on Saturday.
The 23-year-old is anaesthetised in intensive care after he collapsed during the quarter-final at White Hart Lane, which was abandoned due to the incident shortly before half-time.
In a joint statement from the hospital and Bolton Wanderers, it was confirmed that he remained in critical condition after he suffered a cardiac arrest.
The statement read: "Fabrice Muamba remains in a critical condition in intensive care in the Heart Attack Centre at The London Chest Hospital.
"He was admitted to the hospital yesterday evening after collapsing at White Hart Lane, where he sustained a cardiac arrest during the FA Cup Quarter Final against Tottenham Hotspur.
"Fabrice received prolonged resuscitation at the ground and on route to The London Chest Hospital, where his heart eventually started working. As is normal medical practice, Fabrice remains anaesthetised in intensive care and will be for at least 24 hours.
"His condition continues to be closely monitored by the cardiac specialists at the hospital."
The hospital and club released a joint statement on Sunday night saying the player remained in a critical condition.
The statement read: "Fabrice Muamba remains in a critical condition in intensive care in the Heart Attack Centre at the London Chest Hospital.
"There will be no further update tonight."