Nico Rosberg believes it is “too early” for Mercedes boss Toto Wolff to determine whether Andrea Kimi Antonelli is ready to step up to F1.

Mercedes protege Antonelli is understood to be the Silver Arrows’ first-choice to replace seven-time world champion Lewis Hamilton, who is moving to Ferrari in 2025.

The highly-rated 17-year-old Italian is competing in his first F2 season this year with Prema having skipped F3, but 2016 world champion Rosberg has urged Mercedes to take their time before making a final decision.

“Antonelli is definitely a superstar of the future but unfortunately timing-wise it’s really too early for him, and especially too early for Toto to be able to make a decision on Antonelli,” Rosberg told Sky Sports F1.

“He needs to wait until somewhat later in the year as we see how Antonelli does in F2 also, because he does need a really strong season in F2 to make it a possibility for him to go straight to Mercedes.

“Otherwise, if anything, some time at Williams or a team like that would make sense.”

Antonelli has recently tested F1 machinery with Mercedes

Antonelli has recently tested F1 machinery with Mercedes

At the Miami Grand Prix it emerged that an unknown team had lodged a request with the FIA for Antonelli to be granted a superlicence before he turns 18 in August.

This prompted rumours that Mercedes were looking to fast-track Antonelli into an F1 seat with customer team Williams – possibly as early as this weekend’s Emilia Romagna Grand Prix.

But Williams team principal James Vowles denied that Logan Sargeant will be replaced at Imola.

Recent F1 tests with Mercedes have only added fuel to the speculation that Antonelli could get an early promotion.

Wolff has insisted that Mercedes did not request special dispensation for Antonelli from F1’s governing body.

“We haven’t asked for the dispensation,” Wolff told SiriusXM. “I think Kimi needs to concentrate on his F2 campaign and the testing he does with us, that’s the most important.

“[The testing] was good, but early days, there’s no real comparison.”