The UFC’s return to Las Vegas for “International Fight Week” has seen a change to the lineup at UFC 239.

Women’s bantamweight Melissa Gatto (6-0-2 MMA, 0-0 UFC) has withdrawn from her fight against Julia Avila (6-1 MMA, 0-0 UFC). “TUF 28” alum Pannie Kianzad (11-4 MMA, 0-1 UFC) will step in for Gatto on short notice, two people with knowledge of the change told MMA Junkie on Monday.

UFC officials have not yet made an announcement. The reason for Gatto’s withdrawal is not known.

UFC 239 takes place July 6 at T-Mobile Arena in Las Vegas. The main card airs on pay-per-view following prelims on ESPN and UFC Fight Pass/ESPN+.

Nicknamed “Raging Panda,” Avila will be making her promotional debut. In her most recent outing at Invicta FC 32, Avila defeated Alexa Conners via front kick and punches. Four of Avila’s six pro victories have come inside the distance.

Her opponent, Kianzad, was released from the promotion earlier this year following a loss in her UFC debut. The Swedish-born fighter was choked out by “TUF 28” winner Macy Chiasson in the finale of the women’s featherweight bracket on the show.

In May, Pianzad earned a unanimous decision over Iony Razafiarison on the Swedish regional scene at Superior Challenge 19. With the victory, the five-time Invicta FC competitor punched her ticket back to the big show.

With the change, the UFC 239 lineup now includes:

MAIN CARD (Pay-per-view, 10 p.m. ET)

Champ Jon Jones vs. Thiago Santos – for light heavyweight title

Champ Amanda Nunes vs. Holly Holm – for women’s bantamweight title

Ben Askren vs. Jorge Masvidal

Jan Blachowicz vs. Luke Rockhold

Michael Chiesa vs. Diego Sanchez

PRELIMINARY CARD (ESPN, 8 p.m. ET)

Arnold Allen vs. Gilbert Melendez

Sean O’Malley vs. Marlon Vera

Claudia Gadelha vs. Randa Markos

Alejandro Perez vs. Song Yadong

PRELIMINARY CARD (UFC Fight Pass/ESPN+, 6:15 p.m. ET)

Jack Marshman vs. Edmen Shahbazyan

Ismail Naurdiev vs. Chance Rencountre

Julia Avila vs. Pannie Kianzad

For more on UFC 239, check out the MMA Rumors section of the site.