[autotag]Valter Walker[/autotag]’s UFC debut will have to wait.
Walker, the younger brother of light heavyweight contender Johnny Walker, has been forced out of his UFC Fight Night matchup Sept. 23 against [autotag]Jake Collier[/autotag]. He will be replaced by [autotag]Mohammed Usman[/autotag]. The bout takes place at the UFC Apex in Las Vegas.
Two people with knowledge of the booking informed MMA Junkie of the change Friday. They asked to remain anonymous since the promotion has yet to make an official announcement.
Usman (9-2 MMA, 2-0 UFC), who won Season 30 of “The Ultimate Fighter” with a knockout of Zac Pauga, made good in his second octagon appearance when he defeated formerly unbeaten Junior Tafa by unanimous decision in April.
Collier (13-9 MMA, 5-8 UFC), 34, alternated wins and losses in his first 10 UFC fights, but has dropped three in a row. Included in those recent setbacks was a controversial split decision loss to former heavyweight champion Andrei Arlovski.