McLaren is confident that two-time Formula 1 world champion Fernando Alonso's departure will not leave it without a proper benchmark to gauge the competitiveness of its car.
Alonso has elected to step away from F1 for 2019 in the wake of a disappointing campaign last year in which McLaren did not make the progress he had hoped for.
McLaren will field a relatively inexperienced line-up of Carlos Sainz Jr and rookie Lando Norris for 2019, but CEO Zak Brown has faith that the pair will push as hard as Alonso did to allow the outfit to know how much genuine progress it has made.
"Carlos has a lot of experience and it is good that he has been in a couple of different teams," explained Brown.
"Lando has proven that he is extremely quick, so as far as ultimate performance of how fast our race car is, I think those drivers will get the most out of the car.
"They will be able to tell us.
"Someone like Lando does not have the experience of Fernando, nor the type of feedback, and it will take some time for him to develop, but for Carlos it is his fifth year in the sport [F1], so we are comfortable with our drivers."
Sainz drove for McLaren for the first time in the post-Abu Dhabi Grand Prix tyre test last year, and spent time at the factory before the Christmas break to get himself fully integrated.
Brown said he has been impressed by the Spaniard's approach so far, and is convinced he and the team will work well together.
"I started to get to know Carlos before we signed him," he said. "I like him a lot, otherwise we would not have signed him.
"But I have to break it into two things: him as a person and him as a driver.
"As a person, I think he is very well managed, very educated, intelligent and has been around motor racing his entire life. I like his personality, and his attitude.
"He is very approachable, and I think commercially he is very friendly to sponsors, so the off-track package is there so to speak.
"He is very dedicated, asks a lot of questions, and is very mature given his age but I think that is because of how long he has been in F1.
"Then, as a driver, from what we have seen so far, we are very impressed. He is aggressive, he is very engaged with the engineering team, and he wants to know what is happening.
"He spends time on the phone with me, the engineers, and he has done a lot of off-season conversations with Fernando.
"He is very engaged and I think he is very excited. I think he is fully up for joining us on our road to recovery."