Barnett debuted in Antonio Inoki's Inoki Genome Federation (IGF) wrestling promotion in June 2007 with a victory over Tadao Yasuda. He racked up victories against Don Frye and Montanha Silva before suffering his first loss against Naoya Ogawa. The same man he beat earlier in the night. Since the loss, he has been on a winning streak beating The Predator, Hitokui Yoshiki, Tank Abbott, Jon Andersen, Fonseca, Atsushi Sawada, Bob Sapp, Ultimate Mask, Tim Sylvia, Montanha Silva, Bobby Lashley and Hideki Suzuki.