Former world No. 1 Kim Clijsters has assessed the progress of Kazakh tennis player Elena Rybakina and identified the biggest change in her game. According to the Belgian, the decisive shift is not in her strokes or serve but in her improved fitness and court movement, infohub.kz reports.

Clijsters stressed that Rybakina already possessed powerful groundstrokes from the baseline that put constant pressure on her opponents.

"She has always hit the ball incredibly well. When you're standing across the net from her, she hits it so hard, so flat, so deep and so consistently. It's like you're in the line of fire," Clijsters said on the Love All podcast.

At the same time, the former world No. 1 believes Rybakina is now moving faster and looks physically stronger.

"I think she's moving better, her legs look stronger, she's a little bit quicker. I'm not saying she's suddenly going to start defending like Coco Gauff, but it allows her to show her best tennis more often," the Belgian noted.

According to Clijsters, the improved physical conditioning helps Rybakina maintain a high level through long matches and entire tournaments. She stressed that for the Kazakh player's aggressive style, it is especially important to get into position on time and meet the ball at the optimal point.

"The better your fitness, the faster you adapt. In my opinion, that is exactly where the main difference in her game lies, the one I've noticed," Clijsters said.

She also noted Rybakina's progress on serve and a higher first-serve percentage, but singled out physical endurance and strength as the main improvement.

Kim Clijsters is a former world No. 1, a four-time Grand Slam singles champion and a two-time doubles champion. The Belgian won the US Open three times — in 2005, 2009 and 2010 — and triumphed at the 2011 Australian Open. She also won the 2003 French Open and 2003 Wimbledon in doubles. In total, she has 41 WTA singles titles to her name. In 2017, Clijsters was inducted into the International Tennis Hall of Fame.

As a reminder, in the 2026 US Open final Rybakina beat Aryna Sabalenka 6-4, 5-7, 6-2. The title was the 27-year-old's first at the US Open and her third at a Grand Slam, after Wimbledon 2022 and the 2026 Australian Open.