British racing driver Lewis Hamilton poses for a photograph.
Brown, the architect of McLaren's resurgence after a spell in the doldrums, told the Daily Mail he believed Max Verstappen of Red Bull and George Russell of Williams will be recruited by Mercedes in an all-new line-up for 2022.
He added that he would not be keen to offer Hamilton a return to McLaren next year because he was building the team for the future with Lando Norris and Daniel Ricciardo.
Speaking ahead of this weekend's season-opening Bahrain Grand Prix, Brown explained that it would be "bad timing" if Hamilton wanted to find a seat next year.
The seven-time champion's decision to sign only a one-year contract with Mercedes has made his future the subject of intense speculation as the F1 circus prepares for the start of a record 23-race season to run under Covid-19 restrictions.
"If I had an opening, would I put Lewis in the car? Of course, but we are trying to build for the future -- hence this kind of youth-and-experience combination," Brown was quoted saying.
"You feel if you brought Lewis back now it would be for a one or two-year journey and we know we are not ready to compete for championships, so we need to set up a driver line-up that gets us to that position and that when we reach it they are ready.
"Daniel is ready now, of course. I don't think the timing is right for Lewis."
On Mercedes future plans, he added: "I think you will see Max and George there in 2022. I think that's the obvious conclusion.
"Lewis wins title No 8 this year and is the winningest driver in every category. They have a one-year deal with him. George is coming out of his deal and Max has a deal he comes out of."You have Max's experience and youth. You have George's youth. If I'm Mercedes, that's a pretty 'killer line-up' for the next five years."
The six-time world champion and current standings leader has always drawn energy from the big crowds that support him at Silverstone, but this year's event will be run behind closed doors in front of empty grandstands.
The 36-year-old Briton had been out of contract since the end of last year but the negotiations had turned into something of a saga, with questions raised about why it was taking so long.
Vettel, who joined in 2015 with the dream of emulating boyhood hero Michael Schumacher in winning titles with the sport's oldest and most glamorous team, is out of contract at the end of the year.
The Brazil forward defends his team and coach Tite's dance moves in their eye-catching 4-1 victory against South Korea.
"My heart is really singing with joy right now. Our sister is finally free,” WNBA player Chiney Ogwumike said. "This is a monumental moment for everyone who has shown compassion for our WNBA sister over the last 294 days since BG was wrongfully detained.”
The Spanish football federation named under-21s boss Luis de la Fuente as his replacement.
The victory of Morocco over Spain triggered a wild celebration across the Arab world. The victory is being seen as a pan-Arab win. It was not only Doha, where the fans went in the state of euphoria but they flocked the streets from Cairo to Jeddah and Dubai to Damascus.