The upcoming Floyd Mayweather vs. Conor McGregor card has suffered its first blow, as former IBF welterweight champion Shawn Porter (27-2-1, 17 KOs) has withdrawn from his preliminary headliner opposite Thomas Dulorme (24-2, 18 KOs) due to personal issues, which includes a death in the family, according to a recent press release (h/t MMA Fighting).

Porter, 29, was coming off a knockout victory over Andre Berto this past April after losing a decision to undefeated Keith Thurman last year.

“On behalf of Mayweather Promotions we send our prayers and deepest condolences to the Porter family,” Mayweather Promotions CEO Leonard Ellerbe said in the press release. “In boxing we have to deal with curveballs that constantly come at us. Thomas Dulorme has been training hard and is ready to face Yordenis Ugas. Ugas is a tough competitor that shouldn’t be overlooked, and Dulorme is ready. The fight fans are definitely in for an outstanding show between Dulorme and Ugas come Aug. 26.”

Yordenis Ugas (19-3, 9 KOs) will step up on short notice and fill in for Porter on the biggest boxing card of the year. The 31-year-old Cuban is a former Olympic bronze medalist who has not tasted defeat since 2011.

Mayweather vs. McGregor will go down on Aug. 26 live from inside T-Mobile Arena in Las Vegas, Nevada, with the preliminary card airing on FOX starting at 7 p.m. ET and the main card airing on Showtime pay-per-view (PPV) starting at 9 p.m. ET.