A sequel to the 2019 hit "Joker" is in the making, as director Todd Phillips revealed earlier this month, which will feature the character of Harley Quinn alongside Joker portrayed by Joaquin Phoenix, Screenrant reported.

However, reports suggest that Margot Robbie, who starred in the two previous "Suicide Squad" films and also in "Birds of Prey" spinoff as Harley Quinn, will not appear in the new Joker film titled "Joker: Folie à deux". Instead, singer-actor Lady Gaga is reportedly in early talks to portray the role of Harley Quinn in the Joker sequel, according to the report.

This may come as a surprise to many but it is not like Margot is being replaced, instead it has to do with the vision of DC Extended Universe to explore separate universes away from DC Universe. As part of this, we have already seen Batman being played by Ben Affleck and recently Robert Pattinson, Jared Leto as Joker and so was Joaquin Phoenix. So it may be that Margot Robbie will continue as Harley Quinn on one end of the DC Universe and someone else (Lady Gaga?) might on the other.

According to The Hollywood Reporter, "Joker: Folie à deux" is likely going to be a musical, which may explain why Gaga, a pop diva and an accomplished musician, is perhaps a top choice for playing the role of Harley Quinn following her success in the musical drama "A Star Is Born".

Also, all the connections involved in the making of "Joker 2" may also be a reason why Lady Gaga is in talks for Harley Quinn's role. Actor-Producer Bradley Cooper, who was Gaga's co-star in "A Star Is Born", was a producer on Joker and also starred in all "The Hangover" films directed by Todd Phillips, the director of Joker, reports Giant Freakin Robot.

While it is apparent that we will see someone new as Harley Quinn in "Joker 2", it is also likely that Margot Robbie will not be returning to the role in the other DCEU films featuring Harley Quinn for a while. This is because "Suicide Squad" writer-director James Gunn is going to be exploring more successful TV ventures, the report added.