The Nigerian striker revealed the extent of the injury during a livestream with influencer Carter Efe, explaining that the setback resulted from an early collision with Ibrahima Konaté, which forced him off just 10 minutes into the second-leg round of 16 clash.
Osimhen said he will require surgery to repair the broken arm, estimating a recovery period of about five to six weeks before gradually returning to full training and match fitness.
He described how the injury worsened as he tried to continue playing, noting that the pain became unbearable and eventually stopped him from running.
The 27-year-old, who continues to wear a protective mask from a previous facial injury, downplayed the latest setback, saying he has endured far worse in the past, including a major facial operation that left him with multiple screws.
He also revealed that both Konaté and Dominik Szoboszlai reached out after the match, with apologies and messages of concern, which he accepted as part of the game.
Osimhen has since returned to Nigeria ahead of his surgery and expressed gratitude to Galatasaray for their support, describing the club as instrumental in his career revival.
The striker is expected to miss several key fixtures, including matches against Trabzonspor and Kocaelispor, and remains uncertain for the Istanbul derby against Fenerbahçe on April 26. He has recorded 19 goals and seven assists this season across all competitions.
In the same livestream, Osimhen also shared a personal story about former Super Eagles captain John Obi Mikel, recalling how Mikel once invited him to his room after a team meal during his early days with the national team and gave him money—a gesture he described as memorable and encouraging.
He further reflected on his admiration for Nigerian legends, including Odion Ighalo, praising him as a major influence and a respected figure in Nigerian football.