MMAWeekly.com sources confirmed the news first reported by ESPN's Brett Okamoto, who received confirmation from UFC president Dana White.
The good news is that it appears Pettis will avoid surgery.
The injury occurred while he was training with Phil Davis during a promotional trip in Rio de Janeiro, where Pettis was supposed to challenge featherweight champion Jose Aldo on Aug. 3 at UFC 163.
After dropping out of the Aldo fight, Pettis took aim at lightweight champion Benson Henderson at UFC 164, which happens to be slated for Aug. 28 in Pettis’ hometown of Milwaukee.
The problem with that is UFC officials have already announced Henderson would defend his belt against TJ Grant at UFC 164. Pettis has been the No. 1 lightweight contender since January, but asked for and received the featherweight bout with Aldo instead of waiting for Henderson to first get past incoming Strikeforce champion Gilbert Melendez, which he did in April.
“I can be 100-percent ready to fight Benson Henderson in Milwaukee. With all due respect to TJ Grant, Milwaukee is my town and the fight with Ben is the fight everyone has wanted for years,” read a statement that Pettis released to Fuel TV. “If it works out, great; if not, I will get my shot very soon. But I think we all know which fight the fans want to see and the entire city of Milwaukee!”
White immediately shot down the idea, saying that Pettis would not be ready for Milwaukee.
Technically, even with a six-week recovery staring him in the face, Pettis could be ready by Aug. 28, but it would leave little wiggle room for fight-specific preparation and would be a considerable risk if his rehab didn’t go according to plan.
In short, Benson Henderson vs. TJ Grant has already been announced and the UFC isn’t going to risk a pay-per-view on the hope that there are no setbacks in Pettis’ rehab.
Pettis, however, took the setback in stride.
“Injuries are part of the sport. Small tear in my meniscus,” he tweeted. “I was so ready for this fight, this won't stop me! Be back soon.”