Veteran driver Jarno Trulli has hit out at the growing influence of so-called "pay drivers" in Formula 1.It is believed that, despite his 2012 contract, the Italian veteran could be ousted by Caterham in favour of the well-backed Renault refugee Vitaly Petrov.'THAT WAS THE END'Trulli suggested Renault, becoming Lotus for 2012, suffered in 2010 as the team collected sponsorship dollars brought by Russian Petrov and Bruno Senna. "Kubica is a great driver who can get the very best from the car and because of that they were a dark horse." he said."When Robert was out, that was the end. Petrov was not in a position to lead the team and Senna showed that he was not good enough."Senna replaced the experienced Nick Heidfeld mid-season. Trulli commented: "With his experience, Nick scored almost as many points as Petrov even though he (Heidfeld) did only half the season."There is no rule, but it is true that those who pay are less accustomed to suffering. They are less committed."Red Bull team boss Christian Horner, however, said the growing debate about pay drivers was overstated. "For a team it has always been about finding the right balance between financial considerations and talent," he said. "It's something that is as old as F1."