BJ Penn will face a new opponent at UFC 199 following an injury suffered by Dennis Siver in the lead up to their bout June 4 in Los Angeles.
Sources close to the situation confirmed to FOX Sports on Tuesday that Siver was out of the fight following an initial report from BJPenn.com
UFC officials have not yet confirmed the injury or a potential replacement to face Penn at UFC 199.
With Siver out, sources have indicated that a replacement is being sought to face Penn on short notice.
Penn is returning to action for the first time in nearly two years after retiring from the sport following a loss to Frankie Edgar in 2014.
The UFC Hall of Famer decided to make one more go at the sport after teaming up with coaches Greg Jackson and Mike Winkeljohn in New Mexico with a return to featherweight booked for June.
UFC 199 is headlined by a middleweight championship rematch as Luke Rockhold faces Chris Weidman while the co-main event features bantamweight champion Dominick Cruz against Urijah Faber.