Fresh from the successful season 20 run where singer-actress Rumer Willis and pro partner Val Chmerkovskiy won the coveted Mirror Ball trophy, "Dancing With The Stars" rumor mills are starting to roll once again to report the possible roster for next season's competition. 

According to recent speculations, two "Keeping Up With The Kardashians" stars might join the "DWTS" season 21 list of celebrity contestants. One of them is Rob Kardashian, who is not a stranger to the competition after joining the show in season 13. 

A source told RadarOnline that the youngest Kardashian has been given an open invitation to be on the show, and the producers are also considering bringing him and other former celebrity dancers like Willis and Charlotte McKinney together to spend time in the long-running dance reality series. 

But while Rob has not completely ruled out the offer, the insider claimed that the 28-year-old has to lose some weight first before going back to the small screen again. 

Meanwhile, Rob's stepfather Bruce Jenner is also rumored to be joining "DWTS" season 21. Last week, The Hollywood Reporter reported that the former Olympian, who was recently in the news after admitting that he is in transition to becoming a woman, is in serious talks to compete in the show. The news report also claimed that both Derek Hough and Mark Ballas are interested in becoming his partner if he will indeed join the competition. If that happens, this will be the first time in "DWTS" history that a same-sex pairing will compete on the dance floor. 

On the other hand, a fan-made "DWTS" website said that "Taxi" star Marilu Henner will also join "DWTS" season 21. The actress recently made an appearance on "The Today Show" where she was asked if she would consider joining the dance reality show. She said, "I don't know...we'll see?" 

Other rumored celebrity contestants for "Dancing With The Stars" season 21 include Amanda Bynes, Amber Rose, Steve Ballmer, Jalen Rose, Jamie Chung, and the mother of season 20's champ, Demi Moore.