Kell Brook is to undergo surgery on a broken eye socket following his defeat to Gennady Golovkin at London's O2 Arena on Saturday evening.
The 30-year-old, who moved up two weight divisions in order to face the WBC, IBF and IBO middleweight champion, was taken to hospital to undergo an X-ray shortly after the fight.
Scans confirmed that the previously unbeaten Brook suffered severe damage to his eye when taking a flurry of unanswered punches from his opponent, which led to trainer Dominic Ingle throwing in the towel.
Promoter Barry Hearn tweeted in the early hours of Sunday morning: "Thanks for the messages, Special K Brook now left hospital - confirmed broken eye socket op on Monday in Sheffield."
Brook was quick to turn attention to his next bout following the fifth-round stoppage, vowing to take on the winner of the upcoming world middleweight title clash between Saul Alvarez and Liam Smith.