The 145-pound bout will serve as the main event inside Amway Center on Feb. 24, according to the Orlando Sentinel.
Fighting out of Sacramento, California, Emmett is 4-1 overall in the UFC. The victory over Lamas elevated him into title contention.
Stephens (27-14) is just one week removed from an upset knockout of his own, against South Korean prospect Doo Ho Choi in St. Louis. A San Diego-based featherweight, Stephens is riding a two-fight winning streak, with victories over Choi and Gilbert Melendez.
The Orlando card recently lost a high-profile middleweight bout between Yoel Romero and David Branch. Romero (12-2) was pulled from the event to challenge Luke Rockhold for the interim middleweight title at UFC 221 on Feb. 10 in Perth, Australia.