WWE Universal Champion Bray Wyatt and Seth Rollins have already tweeted CM Punk following his debut on WWE Backstage last night.

Wyatt tweeted screenshots from past run-ins with Punk and wrote, "I saw you"

Rollins tweeted, "Fight me @CMPunk"

The WWE on FOX Twitter account responded and offered Rollins time on WWE Backstage to talk it over with Punk. Rollins responded, "Glad to do it. Book me a flight."

As noted, Punk appeared at the end of last night's show in the closing segment and said, "It's as simple as this. Just when they think they got the answers, I change the culture. I'll see you here next week."

PWInsider reported that Punk's surprise appearance was kept a secret to the other on-air talents, except for Renee Young, who introduced Punk, in order to prevent leaks. As we previously reported, Punk's deal is with FOX only, and not WWE. The decision to sign Punk was a FOX call, but WWE obviously gave their blessing. PWInsider added that while Punk and FOX have been in talks, the deal was only finalized in the last few days.

WWE's official press release on Punk joining the show noted that he will appear as a Special Contributor and Analyst beginning next week, making "select appearances" in the studio alongside host Renee Young and analyst WWE Hall of Famer Booker T.

For those who missed it, below is WWE's announcement on Punk's appearance, and a clip from the show, and the related tweets:

CM PUNK JOINS WWE BACKSTAGE ON FS1

"The Best in the World" to Appear as Special Contributor and Analyst Beginning Tuesday, Nov. 19 at 11:00 PM ET

CM Punk, one of the most celebrated WWE Superstars of all time, joins the roster of FS1's WWE Backstage, beginning next week, Tuesday Nov. 19 at 11 PM ET/8 PM PT

Phil Brooks, better known as CM Punk, joins WWE Backstage as a special contributor and analyst. He will make select appearances in studio alongside host Renee Young and analyst Booker T.

"The Best in the World" joins fellow regular contributors Christian and Paige, as well as new correspondent Ryan Satin on the WWE Backstage rotation.

Television's only studio show devoted to all things WWE, Backstage discusses the week's biggest stories with a varied cast of guest and personalities, in addition to breaking news and exclusive behind-the-scenes access to WWE.