Kaitlin Olson asked Phil Keoghan to be on “The Amazing Race” when they filmed the “Hacks” crossover episode that aired Thursday night.

“Kaitlin, who plays [Jean Smart’s] daughter, she had expressed some interest in going,” Keoghan told Page Six in an exclusive interview. “And I started talking through it all with her.”

But Keoghan, 58, said the “It’s Always Sunny in Philadelphia” actress backtracked once she heard “what’s really involved” in appearing on the CBS reality show.

And Olson wasn’t the only person on the “Hacks” set who inquired about going on “Amazing Race.”

“Lots of people expressed an interest, even like crew and everything,” Keoghan told us. “And that is always a good sign.”

He continued, “I do get celebrities approach me and say that they want to be on ‘Amazing Race.’ And then I start to go through the logistics of what that is. Then once they hear a little bit more about what’s involved, they go, ‘Oh, really?’ You shoot 12 shows in 21 days?'”

“I’m like like, ‘Yeah, there’s no there’s no trailer. It’s not a lot of pampering,'” Keoghan added.

The new episode of “Hacks” features Deborah (Smart) and DJ (Olson) competing on a celebrity version of “The Amazing Race” against “Property Brothers” Drew and Jonathan Scott and influencer Trisha Paytas and her partner.

Keoghan makes a cameo — first to kick off the race at the starting line, and then to eliminate Deborah and DJ after they come in last place on the first leg.

The Emmy Award-winning host told us the idea for the crossover event came from “Hacks” creators Paul W. Downs, Lucia Aniello and Jen Statsky, who are all superfans of “The Amazing Race.”

“The producers of ‘Amazing Race’ and ‘Hacks’ were at the same event, and that’s where the discussion was first had,” Keoghan explained. “The idea was floated out there, and then conversations started to happen. Paul was very, very keen on making it happen.”

Keoghan said when producers sent him the script, he gave them notes to make sure the “Hacks” episode was faithful to “The Amazing Race.'”

“I realized there were some things that I wouldn’t say. So I was a bit hesitant in the beginning to be like, ‘Do you mind if I change this?’ But they opened it up to being a collaboration. So I tentatively, with respect, [told them] ‘Could we change that?’ And they were like, ‘Oh, please!'”

But the “best part” for Keoghan was getting to interact with Smart, 74, when the cameras stopped rolling.

“Once we got a take done of any of the scenes that I was in, Jean would just start to riff,” he told us. “And I used to do improv theater. So I suddenly found myself just going back and forth with her.”

Keoghan added, “And it was a real thrill to just be in this surreal moment of having fun.”

The fifth and final season of “Hacks” airs new episodes on Thursdays at 9 p.m. ET on HBO Max.