If Chuck Liddell and Tito Ortiz want to make it to their trilogy fight, they’ll have to be clean.

The two MMA greats will undergo out-of-competition drug testing dictated by the California State Athletic Commission (CSAC) before their third fight in Inglewood, California. CSAC executive officer Andy Foster told MMA Fighting this week that the testing had already begun and will continue.

The samples will be subject to a full World Anti-Doping Agency (WADA) panel. Foster reiterated the commission’s desire to make sure the bout was a clean one after Liddell has been out of action for eight years:

“Just like there should be drug testing for any high-profile fight, there will be for this one,” Foster said. “Chuck Liddell hasn’t fought in some time and hasn’t been part of any drug-testing program recently, as far as I know. We want to make sure the fans are getting a clean, fair contest.”

Liddell and Ortiz were also subjected to a concussion protocol baseline.

Ortiz has been out of action since January 2017 where he submitted Chael Sonnen in Bellator. The 43-year-old has recently embarked on a trash talk-spewing campaign. Liddell finished him twice in the UFC.

The 48-year-old Liddell, meanwhile, has been out of action since a brutal KO loss to Rich Franklin in 2010. He suffered a long and concerning string of KO losses to close out his otherwise illustrious career. He was the UFC’s most popular fighter at one point.