In September 2005, WWE signed Pérez to a developmental contract with Deep South Wrestling.
When WWE ended their affiliation with DSW, he was sent to FCW but sustained a back injury which but him on the sidelines for several months. Upon his return he won a battle royal for the number one contendership for the FCW Southern Heavyweight Championship.
Pérez then formed a tag team with Eddie Colón and became known as the “The Puerto Rican Nightmares” and the first ever FCW Florida Tag Team Champions.
On December 11, Pérez won the FCW Florida Heavywieght Championship when he beat Sheamus O’Shaunessy (Sheamus),Joe Hennig (Michael McGillicutty) and Drew McIntyre in a fatal four way. Soon after he was repackaged as Eric Escobar. He then performed several dark matches before episodes of Smackdown against Jimmy Wang Yang and Kizarny.
In September 2009, Escobar was called up to the Smackdown roster. He immediately won a place as part of the Smackdown team at Bragging Rights when defeated Matt Hardy in his debut. He was then removed from the team.
Escobar then had a brief run as a face after Vickie Guerrero yelled at him, he was then placed in handicap matches and a match against Kane as punishment by Guerrero.
On January 17, 2010, Pérez was released from his WWE contract.