The UFC and FOX Sports have released Chael Sonnen from his contract. The companies released a joint statement on UFC.com announcing that they have terminated their respective broadcasting services agreements with Sonnen after he failed a second NSAC test for banned substances.

Sonnen had announced his retirement following an initial failed test in may and was suspended by the NSAC. The second test had revealed two additional banned substances in his system. Sonnen had been an analyst for FOX Sports' UFC Tonight and other shows. 

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He retired from fighting, who cares what he has in his system after that?

He retired from fighting BECAUSE of what was in his system. Better to bow out then constantly have your legacy tarnished with suspensions.