Bulgarian outlet MMA.bg first reported the booking, and the bout was later confirmed by MMAjunkie.com. The exact date and location of the bout is currently unclear, as the Las Vegas-based promotion has not formally announced the pairing.
Rothwell was suspended by USADA for two years after testing positive for an anabolic steroid of exogenus origin in a pair of out-of-competition drug tests in 2017. The Kenosha, Wisc., native last appeared at UFC Fight Night 86, where he suffered a five-round defeat at the hands of Junior dos Santos. Prior to that, the 37-year-old International Fight League veteran had authored a four-bout winning streak that included finishes of Josh Barnett, Matt Mitrione, Alistair Overeem and Brandon Vera.
A former World Series of Fighting champion, Ivanov entered his promotional debut on a five-fight tear before dropping a five-round verdict to Junior dos Santos in the UFC Boise headliner this past July. The 32-year-old Bulgarian fighter is 16-2 with one no contest over the course of his pro career.