Middleweight champ and Long Islander Chris Weidman has pulled out of his UFC 173 title defense against Lyoto Machida due to a knee injury, the UFC announced Monday.

Weidman, who is coming off of a second-round TKO victory over longtime divisional kingpin Anderson Silva, originally was slated to face Vitor Belfort, but Belfort was forced to pull out after the Nevada State Athletic Commission banned the use of Testosterone Replacement Therapy.

Machida stepped in to take on the native of Baldwin, NY, but Weidman’s knee injury will require minor surgery, and the bout has been moved to UFC 175 on July 5.

UFC 173 is set to take place May 24 in Las Vegas. A replacement headliner for the pay-per-view is in the works, according to a UFC press release.