At times late last season, Daniel Ricciardo would turn to his good friend Brendon Hartley, laugh and say: "Mate, what are we even doing here?"
The Australian was referring to the fact they can now call themselves fellow Formula One drivers. Ahead of the U.S. Grand Prix Hartley had been handed a stunning call-up to Toro Rosso, over seven years after he was cut from the Red Bull programme he and Ricciardo spent their teenage years in. In the time since, Ricciardo has become one of the sport's global superstars, a man seemingly ready to win a world championship given the right machinery.