MMAFighting.com was first to report the pairing. The card is expected to take place at the UFC Apex in Las Vegas and is headlined by a heavyweight clash between Alistair Overeem and Augusto Sakai.
Kelleher saw a two-bout winning streak come to an end at UFC 250, where he dropped a unanimous verdict against Cody Stamann. Prior to that, “Boom” kicked off his 2020 campaign with back-to-back stoppages of Ode Osbourne and Hunter Azure. The 33-year-old is 5-4 during his promotional tenure and 21-11 as a professional overall.
Simon meanwhile, snapped a two-bout skid with a split-decision triumph over Ray Borg in his most recent outing at UFC Fight Night 171 on May 13. The former Legacy Fighting Alliance champion is 5-2 in UFC competition and 16-3 since beginning his pro career in 2014.