An injury has knocked a heavyweight off next month’s UFC debut in Croatia, and a former title challenger is in need of a new opponent.

Ruslan Magomedov (14-1 MMA, 3-0 UFC) has been forced off UFC Fight Night 86 with an injury, and longtime UFC fighter and former title challenger Gabriel Gonzaga (17-10 MMA, 12-9 UFC) needs a new foe for the card.

Magomedov announced his injury on his Twitter account, saying he hurt his knee and “can barely walk.” He posted an x-ray image of his knee, as well. UFC officials are yet to announce the injury or a new opponent for Gonzaga for the card.

UFC Fight Night 86 takes place April 10 at Zagreb Arena in Zagreb, Croatia. It airs on FOX Sports 1 following early prelims on UFC Fight Pass and will be the UFC’s first event in the Eastern European country.

Magomedov, from Russia, was going to be looking for his 10th straight win. After a victory over former UFC heavyweight champion Tim Sylvia in Moscow, he signed with the UFC in 2014 and has won all three of his fights for the promotion by unanimous decision. This past October, he outpointed Shawn Jordan at UFC 192.

Gonzaga fought for the UFC’s heavyweight title in 2007, but lost a decision to Randy Couture. Now in his second stint with the promotion, he has gone 5-4 and recently snapped a three-fight skid with a decision win over Konstantin Erokhin in December at the TUF 22 Finale. His three straight losses came to upcoming title challenger Stipe Miocic, Matt Mitrione and Mirko Filipovic.

With the change, the UFC Fight Night 86 card now includes:

Junior Dos Santos vs. Ben Rothwell

Gabriel Gonzaga vs. TBA

Jan Blachowicz vs. Igor Pokrajac

Bojan Mihajlovic vs. Francis Ngannou

Zak Cummings vs. Nicolas Dalby

Timothy Johnson vs. Marcin Tybura

Alessio Di Chirico vs. Bojan Velickovic

Filip Pejic vs. Damian Stasiak

Damir Hadzovic vs. Mairbek Taisumov

Cyril Asker vs. Jared Cannonier

Ian Entwistle vs. Alejandro Perez

Lucas Martins vs. Robert Whiteford

Maryna Moroz vs. Cristina Stanciu

For more on UFC Fight Night 86, check out the MMA Rumors section of the site.