According to TVLine, the first-time mom will play Stacey, a woman who catches Kutcher's character Walden's eye on the season finale of Two and a Half Men.
But Duff, 25, isn't the one who ultimately keeps Kutcher's interest on the show; instead, E! News confirms, Walden will end up falling for her grandmother, who will be played by Taxi and Celebrity Apprentice star Marilu Henner, 60.
Off-screen, however, Duff is having no problem turning heads after working hard to shed 30 pounds to get her bikini body back following the birth of her adorable 11-month-old son Luca.
"My one trainer helped me lose a sh-t ton of weight," she told Us in February. "I lost like 30 pounds. His name is Gabe Johns and he is amazing. He's a boxing trainer and he comes to my house. I live in the canyon, so we just run. He runs my ass up and down the hill."