Following T.J. Dillashaw being elevated to the main event, Takeya Mizugaki needed a new opponent and he will now face Francisco Rivera at UFC 173. 
The new fight booking was announced by the UFC on Friday.
UFC 173 will come from the MGM Grand Garden Arena in Las Vegas on May 24th and will be headlined by Renan Barao defending the UFC bantamweight title against T.J. Dillashaw.
Rivers (10-2, 1NC) has gone unbeaten in his last six fights (5-0, 1NC) and has won his last two fights by TKO in the second round. He was scheduled to face Raphael Assuncao at UFC 170, but an injury forced him out of the bout.
Mizugaki (19-7-2) is currently on a four fight winning streak and all four of those victories have come by decision. Eleven of his last thirteen fights have gone the distance and his last stoppage victory came in 2011 against Cole Escovedo.
The current UFC 173: Barao vs. Dillashaw card is below.
Main Card: (PPV – 10 p.m. ET/7 p.m. PT)
Renan Barao (32-1, 1NC) vs. T.J. Dillashaw (9-2)
Junior dos Santos (16-3) vs. Stipe Miocic (11-1)
Takeya Mizugaki (19-7-2) vs. Francisco Rivera (10-2, 1NC)
Tony Ferguson (14-3) vs. Katsunori Kikuno (22-5-2)
Jamie Varner (21-9-1 2NC) vs. James Krause (20-5)
Preliminary Card: (Fox Sports 1 – 8 p.m. ET/5 p.m. PT)
Michael Chiesa (10-1) vs. Francisco Trinaldo (14-3)
Chris Holdsworth (5-0) vs. Kyung Ho Kang (12-7, 1NC)
Al Iaquinta (8-2-1) vs. Mitch Clarke (10-2)
Anthony Njokunai (16-7, 1NC) vs. Vinc Pichel (8-1)
Preliminary Card: (Fight Pass – 6:30 p.m. ET/3:30 p.m. PT)
Yves Edwards (42-20-1, 1NC) vs. Piotr Hallmann (14-2)
Sam Sicilia (12-4) vs. Doo Ho Choi (11-1)
Jingliang Li (8-2) vs. Danny Mitchell (14-5-1)