Red Bull say Mark Webber would have been free to have run at Sebastian Vettel in Japan

Christian Horner has said Red Bull were initially unsure which of their drivers' strategies would ultimately win out in the Japanese GP - and insists Mark Webber would have been free to challenge Sebastian Vettel for victory in the closing laps.

Horner added: "When Mark pitted with ten or 11 laps to go and went on to the soft tyre he obviously closed on Grosjean pretty quickly but then came across a bit of traffic and unfortunately he didn't go past Grosjean too quickly. That killed off any chance he had of winning the race." Horner also clarified that Vettel's radio call to Red Bull to "keep him away from me" was in reference to the McLaren of Sergio Perez who the German was coming up to lap, rather than the oncoming Webber. "Sebastian came on the radio and said get Perez out the way because he was coming up to lap him," the Red Bull chief confirmed. "Perez was running at a reasonable pace and Sebastian knew that sitting behind a car, and he'd done a lap behind Perez, was going to damage those tyres. So he said to Charlie 'come on this isn't fair, he's been there for over a lap' and Perez immediately pulled out of the way and he came back on [the radio] and said 'thank you very much.'"