LAS VEGAS » UFC lightweight champion Jose Aldo has pulled out of his title defense against Conor McGregor at UFC 189 on July 11 with a rib injury.

Chad Mendes will face McGregor for the interim title instead. UFC President Dana White made the announcement on Tuesday.

Aldo was hurt while training in Brazil, damaging cartilage in his ribcage. Aldo initially claimed he could still fight despite the pain.

McGregor is among the UFC’s biggest rising stars, and the loquacious Irishman’s bout with Aldo was the promotion’s most anticipated fight of the summer.

Mendes has lost twice to Aldo, but has won every other fight of his mixed martial arts career.