"Top contender Chael Sonnen was not available due to injuries sustained in his fight with Nate Marquardt, so top six middleweight Demian Maia will step in to fight for the title," UFC president Dana White said in a statement.
Vitor Belfort, who was slated to face Silva, recently pulled out of the fight due to a left shoulder injury that he has already undergone surgery for earlier in the week.
MMA Fighting learned from a source Thursday that Belfort had hoped to continue on without surgery, but his doctor recommended that he undergo an arthroscopic procedure to avoid the risk of greater injury. Belfort will be out of training for at least four months.
The No. 1 contender is technically Sonnen, who defeated Marquardt last Saturday at UFC 109 for the shot at the winner of Silva-Belfort following UFC 112. However, Sonnen was not offered the fight due to injuries sustained in the three-round Marquardt fight.
The next worthy title challengers were Marquardt and Maia, but with Marquardt coming off a loss, Maia apparently became the next logical choice. Maia submitted Sonnen last year with a first-round triangle choke at UFC 95.
There is a huge gap in striking ability between Maia (12-1) and Silva (25-4), but Maia has already demonstrated that he one of the most dangerous submission artists in MMA today by opening his UFC career winning his first five fights with submissions. Although Silva is also a BJJ black belt, Maia should be capable of presenting a serious threat to Silva on the ground -- as long as he can put him there. Two of Silva's losses were submissions. One a basic triangle choke and the other a Hail Mary flying scissor heel hook.
Maia first received a chance at fighting Silva last August, but fell short in a 21-second knockout loss to Marquardt at UFC 102. Maia bounced back last Saturday with a decision win against fellow BJJ black belt Dan Miller.