The UFC has officially confirmed Penn's withdrawal to MMA Fighting. The possibilty was first reported by MMAJunkie.com.
Penn and Fitch both agreed to a rematch shortly after their UFC 127 main event fight in Australia finished in a draw.
The fight, though, never came close to coming off.
First, Fitch was forced out due to a shoulder injury, and while a few welterweights including Carlos Condit and Anthony Johnson voiced an interest in replacing him, now an undisclosed injury has also sidelined Penn. It remains unclear if the UFC will try to set up the rematch when both are medically clear.
UFC 132 takes place at the MGM Grand Garden Arena in Las Vegas on July 2. In the main event, bantamweight champion Dominick Cruz returns from a hand injury to defend his belt against longtime rival and No. 1 contender Urijah Faber.