Austrian Alexander Wurz has turned down the chance to drive for Jaguar in 2004 and instead opted to remain at McLaren-Mercedes.
Wurz was favourite to land the second Jaguar seat alongside Mark Webber but the Austrian will now continue in his role as a test and reserve driver.
"It is no secret that I have been on the shortlist for the second race seat at Jaguar Racing, which has been a privilege," said Wurz, who competed in 52 races for Benetton.
"However with Team McLaren Mercedes' 2004 testing programme having already begun I felt it necessary to take my future into my own hands so as to fully focus on the season's preparation.
Wurz, who joined McLaren after losing his F1 race seat, was courted by Jaguar last season before they eventually ditched Brazilian rookie Antonio Pizzonia and signed Wilson for the remaining five races.