Maksim Chmerkovskiy will be sitting out on Monday night's "Dancing With The Stars." His partner, former "Glee" star Heather Morris will continue on and Maks will be temporarily replaced with another pro dancer Alan Bersten for the upcoming performance on Season 24 of "Dancing With The Stars."

Maks Chmerkovskiy is out but Heather Morris will still perform

It all started on Friday at rehearsals when Maksim Chmerkovskiy could be heard in a video of the practice saying, "It's my calf muscle. It just felt like something hit it."

Chmerkovskiy was in the middle of a spin with Heather Morris when his injury occurred.

It's probably a move he's done a million times but this time was different.

Maks let his fans know that he wouldn't be performing in tonight's "Dancing With The Stars" lineup via an announcement on "Good Morning America." This is just week 2 of Season 24 of 'DWTS' and that early into the competition, he and Heather Morris will likely be okay as far as staying in the competition. Those who follow the show know that Maksim Chmerkovskiy rarely gets eliminated early on in any of the seasons so if he must be injured, the timing on this one is probably as good as it gets.

Alan Bersten has been plucked from his work dancing with the "DWTS" troupe to become Heather Morris' partner temporarily. Alan has been with "Dancing With The Stars" for five seasons now and has filled in when dancers have been hurt in the past.

Alan and Heather will be dancing the Jive to Little Mix's "Grown."

What is wrong with Maks?

The extent of Maksim Chmerkovskiy's injury is still unknown. The popular 'DWTS' pro is getting treated for the injury and is expected to be on hand to cheer on Heather Morris as she competes without him later tonight.

There have been reports questioning whether or not Maks will be back for more dancing in Season 24 of "Dancing With The Stars" and that really depends on the extent of his injury.

While it has been reported that Chmerkovskiy is receiving treatment for his calf injury, he's not telling anyone exactly what is wrong. It could be a pulled muscle or something much worse. Fans are hoping that the "Dancing With The Stars" champ updates everyone on when he will return tonight when the newest episode airs.

"Dancing with the Stars" airs Mondays at 8/7c on ABC.