Jenson Button will not drive McLaren's 2017 Formula 1 car before he stands in for Fernando Alonso in the Monaco Grand Prix.
McLaren's reserve, Button has been drafted in from his sabbatical for the sixth round of the 2017 F1 season, which Alonso will miss to contest the Indianapolis 500.
Although it would have been logical for Button to take part in next week's post-Bahrain GP test - or even run in a free practice session in Spain or Russia - to better understand this year's revamped, McLaren thinks there is more to gain by concentrating on simulators.
Rookie Stoffel Vandoorne and development driver Oliver Turvey,who leads the team's simulator programme, will take part in next week's Bahrain test for McLaren instead.
"Jenson spent 17 years in racing in F1," racing director Eric Boullier said, when asked by Autosport why Button was not testing.
"He drove actually the kind of level of downforce that we had today and, going through the differences of the technicalities to drive this year, we agreed the track layout here [in Bahrain], even running practice one in Barcelona, it will not be very useful.
"He is fit, he is ready and having Oliver Turvey next week in the car is part of our fine-tuning the correlation with our simulator.
"The simulator in MTC is very accurate now and we both believe that it is better for [Button] to spend a couple of days in the simulator driving this car model around the streets of Monaco."
Boullier said Button has already done "a couple of days" in McLaren's simulator with its 2017 car, but that will become "a proper job" when he visits the team next week.
"He is very talented. A world champion," he said.
"He had a long experience in F1 and I can guarantee you by lap 10 of Practice 1 he will be OK."
Although McLaren waited two days after Alonso's Indy 500 announcement to confirm Button would be driving in Monaco, Boullier has said the 2009 world champion was the only serious option.
"His first reaction was, 'Great, I am so excited'," Boullier said.
"It was an easy discussion. Very straightforward. He was the choice, he had a contract with us anyway.
"You could feel his excitement over the phone was real and I am happy he will be part of this adventure."