Carlos Sainz is already thinking about his forthcoming preparations to switch to Ferrari over the winter.
The Spaniard is concerned that new testing limits mean he and his next teammate Charles Leclerc will get just a day and a half each of pre-season running.
"We will find a way to minimise the losses, but nothing is the same as testing," current McLaren driver Sainz said in Bahrain.
"It will certainly be my most difficult winter in Formula 1. A day and a half of pre-season is not enough to prepare given the complexity of these cars.
"I can assure you that Fernando, Vettel, Ricciardo and me will be green at the first race of the year."
Sainz admits that running the 2020 Ferrari at the 'young driver test' in Abu Dhabi is probably not possible, and so he and the Maranello team are contemplating other options.
"A test with a Ferrari from two seasons ago may be an option," Sainz revealed, "but I still have a commitment to McLaren so I don't want to be distracted from that."
Less concerned about the situation is quadruple world champion Sebastian Vettel, who is moving from Ferrari to Aston Martin for 2021.
"I probably won't be back in the car until the winter test," the German said on Thursday ahead of the final 'triple header' of 2020 in Bahrain and Abu Dhabi.
"If we really only have three days, as is apparently planned, then it is certainly not a lot but it's the same for everyone. Over the years we have gotten used to doing less and less testing. You can still learn a lot in a day and a half," Vettel added.
