As noted, Friday's WWE SmackDown FOX premiere and 20th Anniversary special saw UFC heavyweight fighter Cain Velasquez make his WWE debut for a quick brawl and showdown with new WWE Champion Brock Lesnar, who had just squashed Kofi Kingston to win the title in the main event of the show. The storyline is that Cain was brought to WWE by Rey Mysterio, following the attack on Monday's RAW season premiere that saw Lesnar destroy Rey and his son Dominick. Cain previously defeated Lesnar for the UFC Heavyweight Title back in 2010, and WWE plans to build off that fight between the two big men.

Cain remains under contract to UFC and has recently expressed interest in fighting again. Despite those comments, it looks like Cain is done with MMA.

In an update, MMA Junkie reports that Cain has made the decision to move on from MMA to focus on his pro wrestling career.

Cain has reportedly informed UFC officials of his intention to withdraw from the US Anti-Doping Agency (USADA) testing pool, which effectively retires him from active MMA competition.

Despite Cain's WWE debut on SmackDown, ESPN reports that Cain has not officially signed a WWE deal yet, according to Cain himself. It was also noted that he has not officially retired from the UFC yet, but that would likely come after the USADA withdrawal mentioned above. As we've noted, Cain has had talks with WWE, AEW, NJPW and AAA.

Velasquez first had talks with WWE following a quick tryout at the WWE Performance Center in 2018, and a ringside appearance at WWE NXT. Things didn't work out and Velasquez ended up signing a short-term deal with AAA. Velasquez saw interest pick up after his two AAA appearances in August and September, and that's when WWE came back to the table.

"We've talked a little bit back and forth and nothing happened," Velasquez told ESPN. "They wanted to see my development. I think they're pleased with what I'm doing now."

We noted before that the 37 year old Velasquez was expected to undergo knee surgery before making any commitment to a pro wrestling promotion. He appeared at SmackDown with a brace on his knee. ESPN noted that Velasquez, who has been training full-time with Pro Wrestling Revolution in San Jose, has been working while suffering from multiple torn ligaments in his left knee. That injury occurred during Cain's knockout loss to Francis Ngannou at UFC Phoenix in February of this year, which was his first fight in a few years. Before that, Cain's last UFC fight came on July 9, 2016 - a win over Travis Browne at UFC 200.

It was noted on MMAFighting.com by Dave Meltzer that Velasquez vs. Lesnar would likely take place at WWE Crown Jewel on October 31 in Saudi Arabia, or at WrestleMania 36 on April 5, 2020 in Tampa, Florida.

For those who missed it, above is video from Cain's debut at the Staples Center in Los Angeles to close the SmackDown FOX premiere.

Stay tuned for updates on Cain's WWE status and future.