Coco Gauff's gritty run at the Italian Open has been nothing short of dramatic, but tennis legend Rennae Stubbs is sounding the alarm on a growing concern that could impact the young star's future. The 20-year-old American has fought through three consecutive three-set matches in Rome, including a hard-fought victory over Mirra Andreeva, to keep her French Open hopes alive. While Gauff managed to cling to her spot in the WTA top four, Stubbs warns that her current playing style may come at a cost down the road.

Stubbs, a six-time Grand Slam doubles champion, has zeroed in on a technical flaw in Gauff's serve and the toll these marathon matches take on a player's body. "Physically, right now she's young. Right now she's going to get away with this and she's going to bounce right back," Stubbs said on her podcast. "But when she gets to 28, 29, 30, 31 if she's playing that long, those matches start to take their toll on your body. As fit and fast and as great an athlete as she is, the more miles she puts on her body on the tennis court because stress affects your body differently when she gets to 30."

The former pro didn't mince words about the potential long-term effects. "The knees will start to get a bit sorer, the hips will start to get a little bit tighter. The shoulders start to have to work a little bit too much. Those are the sort of things that she will have to start really think about going forward," Stubbs added. She also pointed out a subtle but crucial technical issue: "If you watch where her hand is on her grip...she has her finger up like if it's pointing something. There's little technical things. I know she's working with Gavin MacMillan – love the guy."

Gauff's workload in Rome is particularly eye-catching when compared to her remaining competitors. The American has spent nearly nine hours on court across four matches—a staggering figure that underscores her fighting spirit but also raises red flags. Despite ongoing struggles with her serve, she's now just one win away from reaching the Italian Open final, proving she can push through adversity. For tennis fans and young athletes alike, Gauff's resilience is inspiring, but Stubbs' advice serves as a timely reminder: even the brightest stars need to fine-tune their game to sustain a long, healthy career at the top.