Lewis Hamilton is visiting the headquarters of his new team, Ferrari, this week after joining at the start of the year.
The seven-time world champion is expected to make his track debut in a car that is at least 2 years old in midweek, although Ferrari have stated that the exact timing of the run will be weather dependent.
The test will mark nearly one year since Hamilton announced his shock move from Mercedes, where he won six of his seven titles, to Ferrari on a multiyear contract.
"There are some days that you know you'll remember forever and today, my first as a Ferrari driver, is one of those days," Hamilton posted on social media on Monday as he posed at Maranello.
"I've been lucky enough to have achieved things in my career I never thought possible, but part of me has always held on to that dream of racing in red. I couldn't be happier to realise that dream today.
"Today we start a new era in the history of this iconic team, and I can't wait to see what story we will write together."
Exact details of Hamilton's first week embedded in his new team have not been made public, but Ferrari CEO Benedetto Vigna said the driver's arrival was highly anticipated at a sponsor event last week.
"I think if outside there are high expectations, inside there are even more expectations," Vigna said. "There's a lot of excitement and a lot of will to start.
"We are all getting ready, the last things are going to be ready very soon. Lewis is coming to Ferrari, and we are ready -- we are almost ready for everything.
"Changes are always wonderful."
F1's regulations mean teams can test only with cars 2 years or older outside of official preseason testing and Pirelli tyre testing.
Drivers taking part in this year's championship are also limited to 1,000 km of testing in previous years' cars, although team principal Fred Vasseur said last year that he had no concerns about Hamilton, a veteran of 356 Grand Prix starts, getting up to speed.
"For sure we know that we will have a lot of procedures to assimilate during these couple of days, but I think he is experienced enough to do it, that we'll have the advantage to have the simulator," Vasseur said at the end of last year.
"Obviously he will be able to do a race simulation, qualy simulation into the simulator, and to be fully prepared with the steering wheel and the particularities of the race. But honestly, I'm not worried about this. It's not the biggest challenge."
Ferrari will be able to make use of its own test track, Fiorano, which is based within the team's factory walls. However, it is also likely to conduct a private test at the Circuit de Barcelona-Catalunya, home of the Spanish Grand Prix, in a 2- or 3-year-old car later this month.
Hamilton's first taste of his 2025 car is expected to come at its launch on Feb. 19 at Fiorano. Teams are allowed to conduct filming or promotional days in their current cars, allowing them to lodge limited mileage outside of official testing.
All 10 teams will take part in preseason testing Feb. 26-28 in Bahrain, which will be Hamilton's first opportunity to conduct meaningful mileage in the car he will race this year.