Sainz will leave McLaren at the end of the season and join Ferrari after being confirmed as four-time world champion Sebastian Vettel’s replacement in May.
Sainz still has one complete F1 season to race with McLaren after the COVID-19 pandemic delayed the start of the campaign, which is now due to begin on July 5 in Austria.
Drivers moving teams often find themselves being phased out of meetings and having information hidden from them in order to prevent any transfer to a rival operation.
But with the 2020 cars set to be carried over into the 2021 season as part of F1’s cost-saving measures after the pandemic, McLaren Racing CEO Zak Brown said there was less of a need to be as secretive with Sainz.
"We’re racing together in '20, we want to have a lot of success together in ’20,” Brown said on the Sky Sports F1 vodcast.
“He's a professional and we’re professionals. I think if you start holding back information, then you’re not going to have a successful 2020 together, so I think we’ve got to focus on 2020, maximising it, and I think holding back is not productive.
“Our ’21 car is going to look like ’20. Maybe if ’21 had been a brand new car, you then find yourself in an uncomfortable situation of sharing information on next year’s car.
“But next year’s car is effectively going to be this year’s car. So I’m not concerned about the integrity of Carlos. We’ll be an open book.”
Sainz is set to link up with Charles Leclerc at Ferrari next year, ending a successful and harmonious partnership with current McLaren teammate Lando Norris.
Brown said he had zero concerns that Sainz’s pending move would have any impact on the atmosphere at McLaren through 2020, but was less confident Ferrari would be as fortunate.
"Fortunately we have an excellent relationship with Carlos,” Brown said.
“We were very transparent with each other over the winter season. He’s a professional, he’s done a great job for us, his family are our friends.
“Unlike some of these other departures - I think the Vettel-Leclerc Ferrari garage could be quite exciting this year, maybe sometimes for the right reasons but sometimes for the wrong reasons.
“We’ve got a lot of harmony in our garage, and I think Carlos and Lando are very competitive with each other, but have a lot of respect for each other.
“I’m quite proud of how we’ve handled it. I think we’ve become a team that drivers like to drive for. I like to think we’ve created a garage environment where drivers like to come and drive for McLaren.”