Which F1 rival is worrying George Russell and Mercedes in Austria

George Russell has warned that Mercedes will face an increased threat at the Austrian Grand Prix, with high temperatures set to favour one rival in particular.

Mercedes may have topped both Friday practice sessions at the Red Bull Ring with Kimi Anrtonelli, but George Russell was left six-tenths back in sixth place, with the McLaren pair of Oscar Piastri and Lando Norris providing the chief challenge at the front.

Max Verstappen and Lewis Hamilton also bettered Russell, who conceded to having a scrappy lap on his qualifying simulation, but it is the papaya team that has the Briton worried most. 

"It was one lap, so there's nothing to be concerned about," he said. "FP1 was just a decent, solid session. The race pace in FP1, FP2 looked decent. 

"I think the biggest concern for us is seeing the pace of McLaren. Ferrari are there as well. FP1 was a bit of a breeze, but FP2's been challenging."

Pressed on his single lap pace, Russell added: "There was a mistake, so it should be fine."

The weekend has been labelled a "heat Hazard" by the FIA, with drivers allowed to wear the cooling vests. If the elect not to, then in order to maintain a level playing field, they must run an additional five kilos of ballast. 

Commenting further on the McLaren threat, Russell added: "I think they are [a threat]. 

"I think there's a real trend of these hot races that they're strong. We saw it last year; well, we've seen it for years now. 

"Miami was the first real hot race and they arguably could have won. Barcelona, Lando was similar pace to ourselves and Lewis. And then here, they look really strong again. So there's a real trend at these hot races that they seem to step it up, and we maybe take a step backwards.