The Diamond singer, 34, dismissed the professional footballer-turned-TV presenter, 51, after he offered to be the chart-topping songstress' "backup singer".
Michael and Rihanna sat down ahead of her show-stopping halftime gig on Sunday in an interview which has only just aired on television.
"When I heard you were doing the Super Bowl, I was like, okay, you're gonna be at Halftime, I get a front row seat," the ex-NFL star told Rihanna.
Moments later, he burst into tune, singing one of her hits 'Needed Me'.
Michael closed his eyes and waved his arms in the air while performing the tune, as Rihanna watched in disbelief, appearing noticeably uncomfortable.
As she seemed to awkwardly laugh along to the impromptu show, the host asked "Do you need a backup?" as the singer paused before answering.
"You?" she asked, pointing her finger at Michael. "Yeah, well, that was a rehearsal," he replied before singing and dancing yet again.
Finally giving her verdict on his singing, Rihanna said: "It wasn't terrible." To which he replied: "You don't have to lie." Rihanna quipped back: "I've heard worse."
Later in the interview, in a blow to most fans, Rihanna revealed that she had absolutely no "updates" on new music. Her last studio album, Anti, was released in January 2016.
"They (the fans) are waiting. I am excited to actually put new music out but I don’t have any updates for you on that yet," Rihanna admitted.
Asked by Michael if she was able to remain relaxed about performing in front of such huge audiences, she replied: "I have not been able to do that.
"Still, to this day, the camera represents so many people, a huge audience. And the camera at a Super Bowl is one of the biggest audiences."
Rihanna returned to music last year with the single Lift Me Up, recorded for the film Black Panther: Wakanda Forever.