Ricardo Santos will remain in hospital as he undergoes further tests, Bolton Wanderers have confirmed.
The Wanderers skipper missed the match against Bristol City after being admitted to hospital with a viral infection. The defender had been using breathing apparatus.
Santos is now feeling far better but remains in the care of the NHS with further testing taking place. A club update read: "Rico is feeling much improved, but has remained in hospital and is undergoing tests following a viral infection. The skipper has been in touch with staff and team-mates and we wish him well for a continued recovery."