Alves (illness) withdraws from Nelson fight

The co-main event for the UFC's first trip to Denmark is in flux.

Thiago Alves is out of his scheduled welterweight co-headliner against Gunnar Nelson at UFC Copenhagen because of an "unexpected illness," Alves announced Thursday on Instagram. The UFC is seeking a replacement to fight Nelson, sources said.

"I tried everything I could to stay in the fight but my team of doctors wouldn't allow me," Alves wrote. "My goal right now is to get 100% healthy so I can get back to do what I love."

Alves (23-14) added that he expects a return to the Octagon in November or December. The Brazilian slugger has dropped three of four, including a unanimous decision loss to Laureano Staropoli at UFC 237 in May. Alves, 35, is a former welterweight title challenger with 14 years in the UFC.

Nelson (17-4-1) is coming off a split-decision loss to Leon Edwards at UFC London in March. The Iceland native has lost two of three. Nelson, 31, is a longtime training partner of Conor McGregor at SBG Ireland, in addition to his home gym, Mjolnir MMA, in Reykjavik.