Donington Park marked the race debut of Honda's pneumatic-valve engine, which only Hayden was using initially. In the next round at Assen, Hayden ran 3rd from the start and was set to finish there until he ran out of fuel at the final corner, due to an electrical system problem which prevented accurate fuel monitoring. Colin Edwards captured Hayden's 3rd place podium moments before Hayden coasted over the line with no power, to finish 4th place. A heel injury sustained in a motocross crash put him out of two rounds. Relations within the team had already deteriorated, and there was further friction when Pedrosa switched tire suppliers midseason (from the struggling Michelin to the dominant Bridgestone) without Hayden being consulted. Hayden stated "I've never been put in the conditions to choose. Once they told me that I would have just wasted my time had I even only thought about asking for Bridgestone tires. . . I'm not surprised they've given them to him. Besides, at Misano I didn't even have the same fork Dani had. . . No way would I think they'd let me try the new tires".