Lewis Hamilton has urged Red Bull to support Alex Albon and said the team "often spit drivers out pretty quick".
Red Bull demoted Pierre Gasly to Toro Rosso mid-season and promoted Albon for the remaining races.
The 23-year-old Thai-Briton outscored Max Verstappen by 19 points in the six races the pair have spent as team-mates, which is three points fewer than Gasly's 12 races this season.
Red Bull are yet to confirm a second driver for 2020.
Hamilton said: "Alex has got a bright future ahead of him and I hope Red Bull give him the support over the years."
Hamilton, who battled with Albon in the opening laps of the Mexico Grand Prix, said: "It's very, very important because they often spit drivers out pretty quick if they don't always do the job. I hope they're good to him.
"It's also real challenge to go up against a driver in Max that's spoken so highly of by so many people and built up onto a pedestal.
"He has come in so young, with all the difficulties he's had in his life as well. His story is quite an interesting one, succeeding against all adversity. So, on Sunday, it was quite cool to just sit and view him for a second."
Red Bull team principal Christian Horner, who made the decision to swap the drivers after the Hungarian Grand Prix, said: "Alex has scored more points than Max since the summer break, which you never would have expected.
"He is doing a very good job considering it's his first year in Formula 1. He's getting stronger and stronger, he works very hard, he has good feedback in the car and I think he's impressed the whole team with his attitude and application."