Alex Brundle has been stood down from the R-Motorsport Aston Martin Blancpain GT squad ahead of this month's Spa 24 Hours.
The Briton has been replaced in the Swiss entrant's two-car line-up of Aston Martin V12 Vantages by Dominik Baumann for the blue-riband round of the Blancpain GT Series Endurance Cup on July 28/29.
Austrian driver Baumann, winner of the overall Blancpain GT title with the HTP Mercedes squad in 2016, will share the #62 Aston with factory driver Maxime Martin and Marvin Kirchhofer.
Brundle will now "prioritise R-Motorsport's 2019 programme", according to a team statement.
The team is scheduled to switch from the V12 Vantage to Aston's new V8-powered car unveiled at the Le Mans 24 Hours last month.
Brundle said: “I have learnt a tremendous amount in the last three GT3 races and I look forward to continuing my work and partnership with R-Motorsport and turning my efforts and focus to the 2019 programme."
Manor LMP1 regular Brundle had the least GT3 experience of the six drivers signed by R-Motorsport this year, having previously only raced a Mercedes at the Spa in 2013.
Baumann's inclusion in the team is at the moment just for Spa. He will get his first experience of the V12 Vantage during Tuesday's official test day for the 24 Hours.
Guerrieri, Baguette join Honda line-up
Esteban Guerrieri and Bertrand Baguette have been brought in to spearhead the driver line-up in the factory JAS-run Honda NSX GT3 at Spa.
Both have close links with Honda: Guerrieri races a Civic for the Munnich Motorsport squad in WTCR, while Baguette drives for the Japanese manufacturer in Super GT in Japan.
Guerrieri has tested the NSX extensively this year and made his race debut in the car in the ADAC GT Masters series round at the Red Bull Ring in June.
The JAS squad have entered its NSX, which will run under the Castrol Honda Racing banner, in the pro-am category at Spa.
That means that Guerrieri and Baguette will be joined by two bronze or non-professional drivers, who will be announced at a later date.