Hofmann, who had to start from the pit lane on his spare bike, withdrew from last place with 17 of the 28 laps remaining, saying, "I don't have the motivation to fight for the last positions."

This infuriated Luis d'Antin's team, who warned on Sunday that they reserved the right to drop Hofmann for the remaining four rounds of the 2007 MotoGP season - and have now done so.

A to-be-announced substitute rider will thus join Alex Barros from this weekend's Japanese Grand Prix, with Chaz Davies thought to be top of the list. Davies successfully replaced an injured Hofmann at Laguna Seca and recently completed a two day test for Ducati.

Meanwhile, Hofmann now has no chance of staying with the d'Antin team next season and - despite being the only German rider in MotoGP - may be forced to start a new career in Superbike racing.