Taiwo Awoniyi played on despite sustaining a serious injury which in certain instances can be life-threatening, Mail Sport understands.
The Nottingham Forest striker crashed into a post during their 2-2 draw with Leicester City on Sunday and, following several minutes of treatment, returned to action.
On Tuesday, Forest confirmed that the 27-year-old underwent urgent surgery after the extent of the injury was confirmed on Monday and he was rushed to hospital. It can now be disclosed that the injury was of a nature which, in some cases, can prove to be fatal.
After the match Forest owner Evangelos Marinakis was spotted in what appeared to be a heated exchange with manager Nuno Espirito Santo.