Rafael Nadal and both believe mentality is holding him back, ahead of the start of this weekend. Zverev, 28, began 2025 in impressive fashon, reaching the final, only to

Since then, Zverev has not been able to rediscover the form which drove him all the way to the final in Melbourne. His appearances in Buenos Aires and Rio de Janeiro, as part of the ATP Tour's 'Golden Swing' events in Argentina and Brazil, left plenty to be desired. The German's flat showings in South America were followed by early exits at Indian Wells and the Miami Open, where he lost to Tallon Griekspoor and Arthur Fils, respectively. has since overtaken him in the rankings, jumping up to No. 2 in the world. Looking back at his recent frustration, Becker, who coached for three years between 2016 and 2019, thinks many of Zverev's issues are to do with the mental side of the game.

Becker was speaking to former World No. 9 Andrea Petkovic about Zverev's recent form on The latter said: "I've observed it so many times, especially with the great champions, with Novak [Djokovic], with Rafa [Nadal], Roger [Federer], of course, and also with Jannik [Sinner], and sometimes less so with Carlos [Alcaraz].

"But I call it the killer instinct. the killer instinct is about being tough under pressure. Having the killer instinct is being like a predator, where you smell weakness, slam the lid on it, and then it's over."

Becker replied: "I'm convinced he (Zverev) has that killer instinct, otherwise, he wouldn't be number two in the world, he wouldn't have been at the top for years. But right now, I'm only talking about right now, this year, since February, March, April, he doesn't have that killer instinct."

Becker is not the only Grand Slam winner to comment on Zverev's mental strength and ruthlessness. Nadal recently singled out the same issue when asked about Zverev's qualities.

While speaking to , Nadal said: "There are two players who stand head and shoulders above the rest, Carlos [Alcaraz] and Jannik [Sinner]. Others, like [Jack] Draper, are evolving, [Holger] Rune won in Barcelona, Casper [Ruud] played very well in Madrid, [Jakub] Mensik won in Miami. We'll also have to see how [Joao] Fonseca develop

"Zverev is an impressive player, but he hasn't yet managed to win a Grand Slam. Unfortunately, I think it's all in his head, because given his level of tennis, he should have won one by now."

After his loss to French star Alexandre Muller in the second round of the Hamburg Open, Zverev insisted he was positive about his performance, as he was feeling sick before and during the match. He said: "For the fact that I threw up 37 times and had a fever of 39.4 degrees all night, that's actually quite okay.

"I think there are two players in the whole world who would have taken to the court today. I'm one of them. And I'm really proud of that. I was two points away from winning the match. There's a lot to be said in my favour."