In February 2005, Dillinger made an appearance on an edition of WWE Heat in a tag team match against Rosey and The Hurricane.
On the August 19, 2008 episode of ECW, Dillinger made his WWE television debut as a heel under the name Gavin Spears as part of Theodore Long's "New Superstar Initiative" in a losing effort to Ricky Ortiz. On the September 2 edition of ECW, Spears was defeated by Super Crazy. After a three month absence, Spears returned to television on the December 16 episode of ECW, where he lost to Finlay in what turned out to be his final match for the company. On January 19, 2009, Spears was released from his contract.
On September 15, 2013 it was reported that Spears had re-signed with WWE. He was given the ring name of Tye Dillinger. He began to wrestle for WWE's developmental system, NXT. He made his NXT debut in a losing effort against Mojo Rawley. On the January 9 NXT tapings, Dillinger wrestled CJ Parker in a losing effort. Dillinger got his first NXT televised win teaming with Jason Jordan to defeat Baron Corbin and Sawyer Fulton on the March 13 tapings. On the August 7th episode of NXT, Dillinger and Jason Jordan lost in the first round of a Tag Team tournament match to Enzo Amore and Big Cass. On the April 22, 2015 episode of NXT, Dillinger faced Finn Bálor in a losing effort. Dillinger debuted his new "Perfect 10" gimmick, as a heel on the August 12, 2015 episode of NXT, with a win over Solomon Crowe. At NXT Takeover: Brooklyn on August 22, he lost to the debuting Apollo Crews. On the February 18, 2016 episode of NXT, Dillinger defeated Alex Riley. On the April 13, 2016 episode of NXT, he was defeated by Shinsuke Nakamura. On the following week's NXT, he took another loss to Austin Aries. However, 2 weeks later, he defeated Buddy Murphy in singles action, and was scheduled to face the debuting Andrade "Cien" Almas at NXT Takeover: The End, where Dillinger was defeated. Tye then lost a rematch on the June 15 episode of NXT, but he then defeated Wesley Blake on the August 24 episode of NXT. On August 31 episode of NXT, Dillinger defeated Buddy Murphy.
On the September 28, 2016 episode of NXT, after defeating Angelo Dawkins, Dillinger was approached by Bobby Roode, who proposed the two team up for the 2016 Dusty Rhodes Tag Team Classic, a proposition that Dillinger would accept. The following week Dillinger and Roode took on SAnitY (Alexander Wolfe & Sawyer Fulton). During the match Roode walked out on Dillinger resulting in the team losing in the first round, turning Dillinger face in the process. The following week on October 19, Dillinger called out Roode for a match at NXT Takeover: Toronto, which Roode would win. On the November 30 episode of NXT, Dillinger was defeated by NXT Champion Samoa Joe in a non-title match.