The UFC’s August trip to Tulsa, Okla., has been hit by injury.

Welterweight Thiago Alves has been forced out of his co-main event clash with Canadian Jordan Mein. Stepping in for the Brazilian will be Colorado’s Brandon Thatch.

Alves recently returned from a two-year absence from the Octagon, dominating Seth Baczynski at UFC on Fox 11. However, the American Top Team product will be on the sidelines yet again with a knee injury.

Thatch, meanwhile, has taken the 170-pound division by storm. The 28-year-old has run through both Paulo Thiago and Justin Edwards, scoring first-round stoppages in each match-up. The Elevation Fight Team product has stopped all 11 of his wins and also holds a win over current UFC fighter Mike Rhodes.

The 24-year-old Mein already has 37 fights on his resume and will be making his fourth appearance under the UFC banner. The Canadian has stopped 22 of his 28 wins before the final bell, including his UFC debut against Dan Miller. In his most recent outing, Mein edged Hernani Perpetuo at UFC on Fox 11 in April.

UFC Fight Night 49 takes place Saturday, Aug. 23 from the BOK Center in Tulsa. The event will be headlined by a lightweight clash between former champion Benson Henderson and hard-charging Brazilian Rafael dos Anjos. The night’s main card will air live on Fox Sports 1 with the preliminary card streaming on the promotion’s digital network, UFC Fight Pass.