Elbow injury rules out Pettis

As a result, Edson Barboza (15-3) has agreed to take the former UFC lightweight champion's place on the card, which takes place at Chicago's United Centre in 10 weeks' time.

Pettis (18-3) is scheduled to undergo surgery next Tuesday although a timeline for his recovery has not been drawn up yet, his manager Mike Roberts confirmed to ESPN.

The 28-year-old Pettis has struggled with injuries throughout his UFC career and suffered a broken orbital bone during his most recent fight – a unanimous decision loss to Rafael dos Anjos at UFC 185 in March.

Before that, he was out for more than a year with a knee injury.

Barboza's most recent bout was a unanimous decision loss to Michael Johnson in February.