“Dancing With the Stars” Season 21 will be missing some of its ballroom magic Monday night when the show’s longtime host, Tom Bergeron, takes a quick break from his entertainment duties. Erin Andrew’s partner in co-hosting crime revealed Sunday that the reason he’d be missing Week 4 of the hit ABC dance competition was due to a family emergency.

“I’ll miss 2morrow’s #dwts to be at my Dad’s bedside,” he explained on Twitter along with a photo of him and his father from back in day. “He’s given me a lifetime of support. Time to return the favor.”

Bergeron will pass his mic over to none other than Season 19 champion Alfonso Ribeiro who will take over as Andrew’s sidekick during the upcoming installment.

“I will be filling in for @tombergeron tomorrow night on @dancingabc,” the former “DWTS” competitor dished. “I will be there with a heavy heart for my friend Tom and the Bergeron family.”

This won’t be Ribeiro’s first time appearing on Season 21 of the foot-tapping competition. “The Fresh Prince of Bel-Air” actor made his debut on the current installment when he acted as a guest judge during Week 3 of “DWTS.”

“Guest judging on ‘Dancing With the Stars’ is like returning home for me but with a big twist of being on the other side of the judge’s table,” Ribeiro told People magazine prior to planting a seat next to judges Carrie Ann Inaba, Julianne Hough and Bruno Tonioli.

Although Begeron leaves some big shoes to fill during Week 4, we have no doubt Ribeiro will successfully lead the show alongside Andrews. After all, the TV star is no stranger to picking up where Bergeron left off. In 2014, Bergeron revealed that he was leaving his 15-year hosting position at “America’s Funniest Home Videos” -- and that Ribeiro would be taking his place.

“It came together by the people at 'DWTS'  and ‘ABC.’ When [Season 19] of 'DWTS'  ended, there were several producers that all said to me that they felt that this would be an absolute great gig for me,” Ribeiro revealed to the Hollywood Reporter in May. “They suggested to producers of 'AFV'  to take a look at me, and they also mentioned it to Tom, who said, ‘Oh my God, that is just a beautiful idea. I’m on board.’”

The actor went on to explain that Bergeron was nothing but supportive of him as he auditioned for the role. "When I was there to do my test, Tom was there and he was very, very supportive. He let the people there know that he thinks I would be the right one for it. And it’s a show that I’ve been a fan of since near the beginning of it. I would watch it with my kids and I’ve always enjoyed it. So somehow I came up the lucky winner. "

“Dancing With the Stars” airs Monday nights at 8 p.m. EDT on ABC.