The heavyweight tangle was announced overnight by the promotion.
Both men won in short order at UFC 145.
Browne continued his unbeaten stretch with an arm-triangle submission win over Chad Griggs in just 2:29. It was his first tapout win in the UFC, and only the second of his career as he improved to 13-0-1. For his efforts, he won the Submission of the Night bonus.
Rothwell took one of the evening's other big prizes, Knockout of the Night, needing just 70 seconds to conquer Brendan Schaub. It was an emotional win for the longtime veteran, who said afterward that he probably would have retired if he had lost.
Rothwell is 32-8 overall, and while he's been around the MMA scene for over a decade, at 30 years old, he's just nine months older than Browne.
UFC on FOX 4 takes place on August 4 from the Staples Center in Los Angeles. Other announced fights include Lyoto Machida vs. Ryan Bader, and Brian Stann taking on the debuting former Bellator middleweight champion Hector Lombard.