The Belgian midfielder was forced to leave the field on the hour mark after an altercation with Chelsea defender Antonio Rudiger. Unable to continue, Brazilian forward Gabriel Jesus replaced him.
A distraught De Bruyne watched the remainder of the match from the dugout with a visibly swollen left eye.
Despite initial concerns that the 29-year-old had suffered a concussion following the incident, a hospital visit confirmed the extent of his injuries. De Bruyne revealed the news on social media.
His chances of representing his country at the upcoming European Championships will depend on the amount of time it takes for his injuries to heal.
Belgium manager Roberto Martinez was far from impressed upon learning the news about his star player just weeks before the tournament.
He said: "Rudiger is very, very fortunate - when you look at the replay, there's no clash of heads. He's properly leaving the shoulder against Kevin.
"For me, it was excessive force and it was reckless. And it should have been a red card. Kevin is not a player that goes down for no reason. You can see the pain and it's a swollen eye."
De Bruyne faces a race against time to be fit for the tournament with Belgium's first Group B fixture being just 12 days away.
Wearing a face mask similar to the one the aforementioned Rudiger in the final could be a possibility to ensure he makes Martinez's team for the Euros.
Having already captured Premier League and Carabao Cup success under Pep Guardiola this season, De Bruyne watched on as a frustrated Manchester City side were beaten by Chelsea, who won their first trophy under Thomas Tuchel.
Kai Havertz broke the deadlock after 41 minutes, latching on to a pinpoint pass from Mason Mount to take the ball round Ederson and give the Blues the lead. It proved to be the winning goal by the German winger.
De Bruyne will be determined to bounce back stronger with the European title continuing to allude both Manchester City and Guardiola since his switch to English football.
The injury is similar to the one which boxer Billy Joe Saunders suffered, during his defeat to Canelo Alvarez in Texas.
Alvarez caught Saunders with a devastating uppercut in the super middleweight bout, adding yet another clip to the Mexicans highlight reel.
Saunders was unable to see out of his right eye, leading his trainer, Mark Tibbs to throw the towel in at the end of round eight.
The 31-year-old required surgery on his facial fractures and promoter Eddie Hearn has suggested Saunders could retire following the loss.
Saunders posted on his social media channels that the surgery had gone well, but offered no hints as to where his future in boxing lies.