Entertainment TV How Simon Cowell Is 'Building Strength in His Back' 6 Weeks Post-Op as AGT Finale Arrives Simon Cowell is "taking it week by week to ensure the post-surgery healing stays on track," an insider tells PEOPLE By Karen Mizoguchi Published on September 22, 2020 09:00 AM Share Tweet Pin Email Simon Cowell. Photo: NBC Finale week has arrived for America's Got Talent season 15 — with no official announcement of judge Simon Cowell's return yet. Cowell, 60, broke his back on Aug. 8 at his Malibu, California, home when he fell off an electric bike. Hours after the accident, he underwent surgery during which he had a "number of fusions and metal rod" put into his back, a source previously told PEOPLE. During his recovery, he missed the entire four weeks of live quarterfinals and two weeks of semifinals. Though he has not been on set with Heidi Klum, Sofia Vergara, Howie Mandel and Terry Crews, an insider tells PEOPLE that Cowell has been staying productive at his home to prepare for an eventual full return to his work duties. "Simon is swimming many times a day to build the strength in his back since the surgery," the insider says of Cowell, who has also missed the majority of production on Britain's Got Talent which is currently in the semifinal rounds in the U.K. "It was a few weeks before he could get back in a pool after the surgery, but now and for the last couple of weeks, he's been swimming as much as possible," the insider shares. "He's reading a lot and building his muscle strength in his back with the exercise and eating healthy foods but he's taking it week by week to ensure the post-surgery healing stays on track." Along with laps in his pool and a clean diet, Cowell has been working on his walking. "Being able to do things like swimming and taking long walks is big steps forward after an injury like this but he's doing really great," the insider says. "Whenever someone visits, he basically seems to want to race them on a long walk in the garden." RELATED: Simon Cowell Is 'in Good Spirits' as Howie Mandel & Heidi Klum Predict His Return to AGT Throughout his recovery, Cowell has been supported by his longtime girlfriend Lauren Silverman and their 6-year-old son Eric. The family has been spending the unexpected downtime together at their Malibu home, which "Simon loves," the insider notes. Meanwhile, Cowell's AGT family has expressed how eager they are to have him return to the judges' panel. Klum, Vergara and Mandel previously told PEOPLE that they would love for Cowell to come back with Mandel saying, "I wouldn't count him out entirely for the rest of the season." Tuesday and Wednesday are the last two episodes of season 15 with the 10 finalists performing one more time. Roberta Battaglia (who won Vergara's Golden Buzzer), Broken Roots, Cristina Rae (Klum's Golden Buzzer winner), Daneliya Tuleshova, Kenadi Dodds and Archie Williams are among the singers in the live finals. Aerial act Alan Silva, hand balancing trio Bello Sisters, spoken word artist Brandon Leake and dance duo BAD Salsa are the remaining finalists. America's Got Talent airs Tuesdays and Wednesdays (at 8 p.m. ET) on NBC.