A professional competitor since 2011, Rainey has previously competed for Bellator and in the UFC's Welterweight division.
After compiling a 5-0 amateur record, Rainey made his professional mixed martial arts debut in August 2011.
[1] By September 2013, he held an 8–2 record competing for various promotions, most notably Xtreme Fighting Championships.
[7] Rainey faced Muslim Salikhov on April 14, 2018, at UFC on Fox 29, replacing Abdul Razak Alhassan who was removed from the card due to injury.
[10] Rainey faced Tim Means on November 30, 2018, at The Ultimate Fighter 28 Finale.