Jason Lambert is preparing to make his debut as a middleweight and has accepted a proposed bout against Jason “Dooms” Day in a non-televised preliminary bout to take place at UFC 88 on Sept. 6 in Atlanta, Georgia.

FiveOuncesOfPain.com confirmed the news today while speaking with Matt Stansell, one of Lambert’s managers with the North County Fight Club.

Lambert has an overall MMA record of 23-8 and a career UFC record of 4-3. He started in the UFC with an undefeated record of 3-0 with wins over Terry Martin, Branden Lee Hinkle, and Rob MacDonald before losing to Rashad Evans at UFC 63.

Lambert rebounded from the loss against Evans with an upset knockout over Renato “Babalu” Sobral during UFC 68 but currently finds himself in the midst of a two-fight losing streak. His most recent loss took place against Luiz Cane at UFC 85 this past June.

Day made his UFC debut at UFC 83 this past April following a controversial decision win over David Loiseau while fighting for the now-defunct Hardcore Championship Fighting promotion. Considered the underdog at UFC 83 against Alan Belcher, Day managed to pull off another upset by finishing him with a TKO at 3:58 of round 1.

Day returned to the Octagon in June at UFC 85 in a featured contest vs. Michael Bisping, losing via TKO at 3:42 of round 1.

UFC 88 is scheduled to be headlined by a light heavyweight bout between Rashad Evans and Chuck Liddell. Rich Franklin is also scheduled to return to the light heavyweight division in another featured bout vs. Matt Hamill. Other main card bouts include Nate Marquardt vs. Martin Kampmann (just officially announced by the UFC this morning), Dan Henderson vs. Rousimar Palhares, and Karo Parisyan vs. Yoshiyuki Yoshida.

Currently expected for the undercard in addition to the Lambert vs. Day fight are bouts between Matt Brown vs. Dong Hyun Kim, Kurt Pellegrino vs. Thiago Tavares, Roan Carneiro vs. Ryo Chonan, and Tim Boetsch vs. James Lee.