Rountree was expected to face Gökhan Saki on December 30, 2017 at UFC 219. However, Saki was forced to pull out, citing knee injury, and was replaced by Michal Oleksiejczuk. He lost the fight by unanimous decision. However, after the fight, it was revealed that Oleksiejczuk had tested positive for clomiphene, an anti-estrogenic substance. As a result, the Nevada Athletic Commission (NAC) officially overturned the result of the fight to a no contest.