It turns out Josh Barnett’s release from the UFC has everything to do with the U.S. Anti-Doping Agency.

On Wednesday, two people with knowledge of the situation, including a UFC official, informed MMAjunkie of Barnett’s release. In response, Barnett told ESPN.com that his departure was still in the process of being finalized. The veteran heavyweight requested to be released because of his lack of trust in USADA, which oversees the promotion’s anti-doping program.

Three months ago, Barnett became the first UFC fighter to be exonerated by USADA for a failed drug test, receiving only a public warning. Barnett expressed dismay with the results management process and had previously told MMAjunkie he didn’t trust USADA.

He reiterated that to ESPN.com as the reason for his pending release.

“It’s true that I have asked for my release, and we are discussing the terms now,” Barnett said. “Zuffa (parent company of the UFC) has been fantastic and above-board since I re-signed with the company (in 2013). Every promise made has been kept, and I have no disparaging words for them. After everything I went through with USADA, and my vindication in that case, I don’t feel comfortable giving the control necessary to USADA that would continue my career in the UFC.”

In late 2016, an out-of-competition test of Barnett revealed the presence of ostarine, a selective androgen receptor modulator (SARM) that mimics anabolic agents and is banned year-round. Although USADA found he was the victim of a contaminated supplement, he faced a four-year suspension before ultimately going to arbitration with USADA. It took 15 months for his name to be cleared.

An independent arbitrator took note of Barnett’s meticulous record keeping of supplements and found he was not guilty of knowingly taking ostarine. Barnett later sued the supplement maker.

Barnett (35-8 MMA, 7-3 UFC) most recently defeated ex-champ Andrei Arlovski at UFC Fight Night 93 in September 2016. Barnett’s release marks the end of a five-year run with the promotion.

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