Serena Williams' ex-coach Rennae Stubbs sends concerning message about Novak Djokovic's future after Serb's Madrid Open heartbreak

Serena Williams' ex-coach Rennae Stubbs has sent strongly-worded messages concerning Novak Djokovic's future. This came after the Serb’s disappointing opening-round exit at the Madrid Open against Italy's Matteo Arnaldi.

Djokovic's time is not going well, as he seems far from his peak form, with retirement concerns looming due to his age. His 3-6, 4-6 loss to Arnaldi in Madrid marks his second consecutive opening-round defeat, following a similar exit at the Monte-Carlo Masters.

Stubbs is one of those concerned about the Serb’s future and took to X (formerly Twitter) to share her thoughts. She pointed out that his unforced errors are on the rise, making his opponents less afraid of him, which she believes is contributing to his struggles.

“The worry index continues for Novak, as i pointed out on my latest podcast. He’s making way too many unforced errors (32 today) & NOT locking down in the biggest moments. Guys are not intimidated anymore because of that & that's the biggest key for these player, they see/feel it,” she wrote.

The former doubles specialist, who once coached the legendary Serena Williams, added:

“When you lose your aura, and in turn are NOT locking down & making these guys suffer, like double-faulting 2 x in a row to drop serve in the 1st set. U would never see that from Nole at his best. How do u get that confidence back? U have to win & I worry the motivation is gone.”

Rennae Stubbs believes Novak Djokovic can still win a Grand Slam, but there's 1 key element missing

Novak Djokovic pictured at the 2025 Madrid Open | Image Source: Getty

Serena Williams' ex-coach Rennae Stubbs continued talking about Novak Djokovic on X and made her feelings known on whether the Serb could win another Grand Slam. She said she thinks the chances are definitely there, but pointed out that one key element is missing right now, which is his lack of confidence at the moment.

Stubbs wrote:

"Do I think he can still win a Slam? Of course! He’s the greatest player of all time BUT it’s getting harder & harder every week because I don’t care who u are, you can’t buy confidence! U have to earn it & currently his confidence is getting chipped away at more & more."

She added:

"ALSO! Arnaldi played awesome!!! But looking at the match with a fine-tooth comb, the way Arnaldi handled the tough moments, like down 0-40 on serve after breaking in the 2nd, he locked down & was the better player & thats where the shift has happened. It’s not Novak anymore."

Djokovic will now shift his focus towards preparing for the Italian Open, followed by the year's second Major at the French Open.