Imola, Italy (AFP) — Lewis Hamilton admitted Thursday that he had underestimated how difficult it would be for him to adapt to life with Ferrari after 12 years with Mercedes.

The 40-year-old seven-time world champion won six of his championships with the “silver arrows” before his sensational exit last year.

“I anticipated it would be very tough because I’ve joined a team before, and I came in with a really open mind.

“I just didn’t know how tough it was going to be,” he admitted at Imola ahead of this weekend’s Emilia Romagna Grand Prix.

“I knew it was going to be challenging, and it’s as challenging as it could ever be on all fronts.”

After six races this year, he is still seeking a first podium finish in a Grand Prix and is seventh in the drivers’ title race behind Kimi Antonelli, the Italian teenager who replaced him at Mercedes.

Hamilton cut a low-key figure on arrival in the paddock at the Autodromo Enzo e Dino Ferrari, the team’s home circuit, and conceded that “there’s still a lot of work that needs to be done” if he is to revive his form.

“The championship?” he said. “There’s still a long, long way to go. From all my years of experience, when you’re over 100 points behind at this point in the season, with a car that’s up against a car (McLaren) that is dominant, you have to assume that you’re not necessarily fighting for a championship win.

“But things can turn around.”

‘Stay vigilant’

Hamilton trails series leader Oscar Piastri of McLaren by 90 points.

Ferrari plans to add an upgrade package to their car this weekend, with a major one expected in Spain in two weeks’ time, but Hamilton said he is unsure of their value or potential.

“At the moment, we don’t know, but we want to get closer, and we can’t shut the door on any ideas. We have to keep our eyes and our heads up and stay vigilant.

“We have to push with the expectation and goal of winning, finding the tenths to turn things around. You have to believe it.”

Teammate Charles Leclerc withdrew from his media duties on Thursday due to illness.

In a statement, Ferrari confirmed that the Monegasque driver was out of sorts but was expected to be fit to drive on Friday.

“Charles is feeling unwell and will not be coming to the track today,” it said.

“He will rest and focus on recovering, and we expect him to be in the car tomorrow.”

Leclerc’s absence added to the Italian team’s woes ahead of their first “home” race of the season.

Ferrari, with marquee signing Hamilton struggling to shine, are already 152 points behind leaders McLaren in the constructors’ championship after finishing last season with only 14 points behind them.

After six races, they have only registered one podium finish — Leclerc taking third place at the Saudi Arabian Grand Prix in April — and one sprint victory, by Hamilton in China.

Leclerc is in his seventh year with Ferrari after joining from Sauber in 2018 and is widely thought to be one of the fastest drivers in the paddock, but without a car to match his talents.

He has won eight Grands Prix with Ferrari and claimed 44 podium finishes and 26 pole positions, but he has been unable to overcome the dominance of four-time champion Max Verstappen and Red Bull in the “ground effect” era.