Mercedes team boss Toto Wolff has backed George Russell to bounce back after former Red Bull motorsport adviser Helmut Marko suggested the Briton would never recover from being outshone by teammate Kimi Antonelli.

Antonelli leads Russell by 123 points at the top of the Formula One standings with 125 available after winning Sunday’s US Grand Prix in Texas. The Italian can become the sport's youngest-ever champion in Mexico City this weekend and the first from his country since 1953.

The 20-year-old has claimed nine wins in his second season compared to three for Russell, who entered the year as bookmakers' favourite.

"Russell is no longer the number one driver," Marko, who left Red Bull last year, told Sky Germany prior to Sunday's US Grand Prix, where Antonelli won from pole as Russell finished eighth following a five-second penalty.

"Antonelli has quite clearly taken that spot from him... I doubt whether he'll ever have another chance at the world title or be given number one status anywhere," added the 83-year-old.

Wolff noted that while he respected the opinion of his fellow Austrian "not-so buddy", Marko was wrong.

"George has all the ability. I think the car doesn't suit him," he told reporters at the Circuit of the Americas.

"At the beginning of the season it's maybe difficult to cope with a situation where you're feeling like this is my year to come and then you have this wunderkind on the other side (of the garage) that starts to really chip away.

"I believe that in a new season, George — if we provide him with a quick car — has absolutely what he needs to win a championship.

"I think it's a bit too easy to say let's forget about all these years where he won in F2 and in F3, in his rookie years in the European championships back-to-back in kart. That's all still there."

Russell now faces a significant battle to hold on to second spot in the drivers’ standings as he is just one point ahead of Lewis Hamilton, while Max Verstappen is only five points further back, with Charles Leclerc just three points behind the Dutchman.