Oct.31 (GMM) Red Bull and Toro Rosso have denied rumours they could shake up their Formula One driver lineups for the final two races of the 2013 season.

Speed Week reports rumours from the Abu Dhabi paddock that this weekend's race at Yas Marina could be Mark Webber's last in F1.

The Australian, who has admitted suffering with motivation problems, has already announced his switch for 2014 to Le Mans.

He will be replaced by countryman Daniel Ricciardo, but the latest rumour is that the 24-year-old could made an early move from Toro Rosso ahead of the US Grand Prix in Austin later this month.

That would free up a seat for the last two Grands Prix of 2013 at Toro Rosso, who have signed inexperienced youngster Daniil Kvyat for next season.

"I think it's nonsense, and I know nothing about it," Toro Rosso boss Franz Tost is quoted as saying.

"Anyway, Daniil has no super licence, so how can he race?" the Austrian added.

However, Tost's argument about the super licence does not bear up to scrutiny.

Auto Motor und Sport reports that, because Toro Rosso wants to field Kvyat in Friday practice in Austin and Brazil, a test in a 2011 car has been lined up for the 19-year-old at Misano in early November.

"That's right," Tost confirmed, "but the story for this is that he will do the first practice for us in Texas and Brazil."

Red Bull Racing, meanwhile, denied that Abu Dhabi will be Webber's last Grand Prix.

"Mark Webber will drive the last three races for us," the team told Speed Week.