Forest striker Awoniyi has surgery after post collision
The Nigeria international, 27, collided with the post in the 88th minute of the 2-2 draw at the City Ground as he attempted to get on the end of a cross from Anthony Elanga while under challenge from the Foxes' Facundo Buonanotte.
"The club can confirm Taiwo Awoniyi has undergone urgent surgery following an abdominal injury sustained during Sunday's match against Leicester City," said a Forest statement.
"Everyone at Nottingham Forest sends their best wishes to Taiwo.
"The club will provide further updates when appropriate."
Awoniyi, who joined Forest from Union Berlin in June 2022, had only been on the pitch for five minutes having come on as a late substitute for Ibrahim Sangare.
He tried to play on following prolonged treatment on the field, but the full extent of his injury was only discovered by medical staff on Monday.
The way Awoniyi's injury was dealt with during the game was cited by Forest owner Evangelos Marinakis as the reason why he stormed onto the pitch after the full-time whistle to confront head coach Nuno Espirito Santo.
With Forest chasing a late goal which would have bolstered their bid to quality for the Champions League, Awoniyi returned to action but was unable to move freely -- and Marinakis was unhappy a substitution was not made.
"Everybody -- coaching staff, players, supporters and including myself -- we were frustrated around the injury of Taiwo and the medical staff's misjudgement on Taiwo's ability to continue the game," said Marinakis in an Instagram post issued later Sunday.
"This is natural, this is a demonstration of the passion we feel for our club."
The draw with Leicester, already relegated from the Premier League, took Forest's bid to qualify for the Champions League out of their own hands but did assure of them of a top-seven finish that will guarantee European football next season.
But if two-time European champions Forest win their last two league fixtures, including a final-day clash with Chelsea, it might not be enough for them to qualify for the Champions League unless at least one of Aston Villa, Manchester City or Newcastle also drop points along the way.