Miller and his tag team partner Steve Lewington lost to John Morrison and The Miz for the WWE Tag Team Championship on February 15, 2008 at an FCW show. Miller and Lewington then advanced to the finals of a tournament for the inaugural Florida Tag Team Championship in February 2008. Miller and Lewington defeated Brandon Groom and Greg Jackson and The Thoroughbreds (Johnny Curtis and Kevin Kiley) to reach the finals. On February 23, 2008, Miller and Lewington lost to The Puerto Rican Nightmares (Eddie Colón and Eric Perez) in the finals. On September 11, teaming with Joe Hennig, he won the FCW Florida Tag Team Championship. As champion, he changed his ring name to Sebastian Slater. On October 30, 2008, Slater and Hennig lost the title to The New Hart Foundation (Harry Smith and TJ Wilson) in Tampa, Florida. He later returned from injury and defeated Justin Angel. On August 13, 2009, at the 50th FCW TV taping, Miller defeated Tyler Reks to become FCW Heavyweight Champion. Slater lost the FCW Heavyweight Championship to Justin Gabriel in a two out of three falls match at the September 24, 2009 TV taping.