Speaking ahead of this weekend's Canadian Grand Prix, Pascal Vasselon, Toyota's Senior General Manager Chassis, has cast further doubt on Ralf Schumacher's future with the German team.

Previously, Pitpass reported that according to its sources Schumacher has been given a stark ultimatum, improve in the next two races (Canada and USA) or you're dropped.

Although the team can account for Jarno Trulli's disappointing weekend at Monaco, the same cannot be said of Schumacher, with Vasselon claiming that with the team, having made a significant step forward at the Barcelona test, could find no "obvious limitation" of the TF107.

"From the very beginning we were struggling to give Ralf a car which was comfortable over the bumps and kerbs and that affected his confidence," said Vasselon. "He felt very low grip as well.

"We can actually go a long way with a lot of parameters," he continued. "We have a very wide window in terms of weight distribution, camber and suspension stiffness and we are not really limited. It was connected with general grip and confidence but there was no obvious limitation of one parameter.

"In Monaco we had problems," he admitted. "After Barcelona practice Ralf had made a step in terms of confidence but for different reasons there were problems in Q1. In the Barcelona race he was capable of running competitively but he was hit on the first lap after he had already made up some places. His pace was good when he was free and that was confirmation that we had made a step.

"Monaco we are looking into," he added, "but the track is a bit of a one-off, whereas if you've made a step at Barcelona it usually translates to other circuits."

Despite claims that should Schumacher be dropped his seat would be given to (test driver) Franck Montagny, Pitpass' source insists that Kazuki Nakajima, currently test driver with Williams, would be given the drive.