On 15 November 2006, Honda Racing announced the signing of Klien as their test and reserve driver for the 2007 season. The Austrian made his debut for the Japanese works team at the Circuit de Catalunya, during the early pre-season testing during late November 2006. At the 2007 British Grand Prix, he replaced the injured Jenson Button for the second free practice session on Friday. On 11 July 2007, Klien was released by Honda F1 to test with Spyker with a view to replacing Christijan Albers who was released because of sponsorship problems. However, the seat went to Japanese driver Sakon Yamamoto.