The roster for the next batch of celebrity hopefuls who will vie for the Mirror Ball trophy in "Dancing With the Stars" season 21 is starting to get filled. At the moment, three celebrities are confirmed to be joining ABC's long-running celebrity dance competition for its 21st season. 

The first one to announce her quest to get the coveted Mirror Ball trophy is the popular wildlife conservationist and Australian TV personality Bindi Irwin. The 17-year-old actress and host of several wildlife series dropped by the set of "Good Morning America" early this week to announce her participation in the dance reality competition.

Irwin is the daughter of the late "Crocodile Hunter" Steve Irwin.

Also, the American Pharoah champion Victor Espinoza will exchange his riding boots with a pair of dancing shoes in the next season of "Dancing With the Stars." The Triple Crown winner visited ESPN2's "SportsNation" to reveal the announcement. 

Another "DWTS" season 21 contestant was exclusively announced by US Weekly. This time, Nick Carter from the popular 1990s boyband Backstreet Boys will try to impress the judges by showing the dancing prowess that he became famous for. 

Carter also confirmed the news in his own Twitter account by posting a compilation of some of the signature Backstreet Boys dance moves, saying: "You ain't seen nothing yet." 

Meanwhile, recent reports are saying that former Food Network star and popular southern kitchen queen Paula Deen will join "Dancing With the Stars" next season. Deen had been part of several "DWTS" casting rumors in the past, but she never confirmed nor denied those rumors. Now, a source exclusively told US Weekly that she finally decided to try her luck on the dance floor. 

ABC has yet to comment about Deen's participation in the dance reality series, as well as the rumors linking Chaka Khan in the show. 

The rest of the celebrity contestants and their pro partners for "Dancing With the Stars" season 21 will be announced in "Good Morning America" on Sept. 2, while the two-part season 21 premiere will be aired on Monday, Sept. 14.