The pop superstar is currently wowing fans in Bradley Cooper's movie remake of "A Star Is Born", playing the role Streisand previously tackled in 1976, and now GaGa is said to have been tapped to lead the cast as Fanny Brice in a long-awaited stage revamp of "Funny Girl".
Rosie shared the surprise news during a weekend (October 06-07) appearance at The Paramount theatre in Long Island, New York, where the comedienne claimed she would be portraying Brice's mum, according to multiple reports.
The gig would mark her first time back on the "Great White Way" since appearing in a 2004 revival of "Fiddler on the Roof".
Representatives for both GaGa and O'Donnell have yet to confirm the claims, but stage bosses have been trying to resurrect "Funny Girl" on Broadway for years.
"Six Feet Under" actress Lauren Ambrose was initially cast in the lead role in 2011, with the musical set to start with a run in Los Angeles in 2012, before moving to the famed New York theatre district, but financial issues caused the reboot to be abandoned.
In 2014, TV mogul Ryan Murphy revealed he was actually in talks with his "Glee" star Lea Michele to launch "Funny Girl" for a new generation of fans, but the Broadway project never materialised, and last year, the actress suggested Murphy no longer had the rights to the musical.
Streisand played the part of Brice in the original 1964 stage show, which ran for three years and earned eight Tony nominations. The legendary singer/actress reprised the role in the 1968 film adaptation, which earned her the Academy Award for Best Actress in 1969.