The 27-year-old Nigerian collided with one of the posts in the 88th minute of Sunday's Premier League match at home against Leicester (2–2) and subsequently received treatment for several minutes on the football pitch.
The collision with the post resulted in Awoniyi sustaining an injury to his abdomen. According to the BBC, it involves a ruptured intestine. He has since required surgery for several days, starting on Monday. On Tuesday, he was placed in an induced coma, from which he emerged on Wednesday evening.
Nottingham's owner has criticized the medical personnel following the decision to let Awoniyi, who came on in the 83rd minute, continue playing in the weekend's match.