Chris Martin Calls Rihanna 'The Best Singer of All Time' Ahead of Her Super Bowl Halftime Show

Riri takes the biggest stage in music Sunday at State Farm Arena in Phoenix, Arizona.

Chris Martin has anointed Rihanna "the best singer of all time." Suffice it to say, he's a fan. A big, big fan, actually.

The Coldplay frontman spoke to Zane Lowe on Apple Music 1 and shared the high praise while discussing why it's a big deal that the Barbados Babe agreed to take on the challenge of performing on music's grandest stage, the Super Bowl Halftime Show.

"I don't know Rihanna very well. I'm mainly just a fan, and we have performed with her a few times, and you're right, it is rarer and rarer for her to just sing, which is what makes it even more special, and in a strange way, it shows that she really, really wants to do it," he said. "No one can make Rihanna do anything at this point, and so I think the fact that she has chosen to do it now, when her stock couldn't be ... you have to be an idiot not to recognize that she's the best singer of all time. So it's hard for me, I'm very biased because I'm such a big Rihanna fan. I mean, I think she could just walk out in sweatpants and sing, and that would be just great."

Ahead of her first live performance in front of a packed stadium in years, Riri knows a lot's riding on Sunday at State Farm Arena in Phoenix, Arizona. A source tells ET the 34-year-old singer is "nervous" but excited for the challenge.

"She knows this performance will be iconic for years to come and it will live on forever," the source said. "She's been tweaking things and saying how this is going to be craziest 17 minutes of her life. She is nervous, but also knows she is going to kill it."

Coldplay's no stranger to the bright spotlight that is the Super Bowl Halftime Show. They performed in 2016 at Super Bowl 50, with Beyonce and Bruno Mars as special guests. While Bey earned critical acclaim for her performance, the same could not be said about Coldplay. One critic called the band's performance "a musical snooze" as well as "inexplicable, indecipherable and unnecessary."

All these years later, Martin reveals he hasn't watched the performance.

"I've never watched it back. I have a very strange sensation about the Super Bowl performance because given the limitations, we had certain limitations. It was daytime, you have to do certain sponsor stuff, on and on," he explained to Lowe. "The stage has to be a certain color because it's this anniversary, so there was a lot of things that we had to navigate around, and we got quite a hard time afterwards from some people who didn't really like it, which was hard to take at the time. But then at a certain point I realized, 'Well, we did exactly what we wanted to do given all those limitations.'"

He continued, "We would do exactly the same way, I think. We would ask the same guests. I don't mind the fact that I'm going to be in a dance off with Beyonce and Bruno and lose, that's the point. Someone has to represent the non-dancing humans. So I think I sort of became really at peace with it a few weeks afterwards, but the initial 12 days was really weird."

One thing fans can't argue, Martin knows exactly what it feels like to be under the Super Bowl Halftime Show spotlight with millions specifically tuning in for the show.

"What does it feel like? I mean, it's masses of adrenaline. I think if all things in life, if you're a fan of something and then you get to do it's extra charged -- and we dreamed of doing the Super Bowl for so long, and it's one of the only cultural events in America that everyone is watching," he said. "There aren't that many things that everyone in the country gets into, so there's just an energy around, and then there's all these gigantic people who are playing the actual game, so that's exciting. And I think once you get your microphone and the ready, steady, go, then you're just in normal work mode. But there's just a general heightened air and an intensity because it's only 12 minutes, and then it's all over so quickly."