The multiple Grand Slam-winning tennis player was heard in a leaked clip of a new hip-hop track yesterday (May 11).
Lyrics in the track include: "I ball hard no tennis racket/ I can't see these haters through my Gucci glasses/ I make hits like bat in practice/ Baby like Serena is you really rapping?"
Rapper The Game said that Williams had "raw" skills and that she is a "really talented artist".
"You shouldn't expect her to come with anything less than the official rap bars," he told TMZ.
Serena Williams reportedly recorded a number of tracks in Florida last year at the B Major Music Group studio.
The Game is expected to release his fifth studio album F.I.V.E.: Fear Is Victory's Evolution later this year.
Listen to Serena Williams's untitled track below: