Reigning Formula 2 champion Felipe Drugovich is in pole position to replace Lance Stroll in next weekend's Bahrain season opener.
Stroll, the son of Aston Martin team owner Lawrence Stroll, has been sidelined for the start of pre-season testing this week by a bicycle accident.
The team, and 24-year-old Stroll, have not disclosed the details of the injury. But Drugovich, a new Aston Martin reserve, will be on duty in Stroll's place on the opening day of proceedings in Bahrain on Thursday.
The other Aston Martin reserve is former McLaren racer Stoffel Vandoorne - but he is unavailable for Bahrain testing due to his Formula E duties in Cape Town this weekend.
"We discussed the situation, but I knew it and the team knew it - I would not be able to do the testing in Bahrain unfortunately," Vandoorne told the Belgian broadcaster RTBF.
However, the 30-year-old Belgian will be in Bahrain for the start of the 2023 race season.
"It's quite a difficult scenario for me," Vandoorne admits. "If Lance is not available, I wouldn't be surprised if Felipe did the race.
"It's a little frustrating for me, but on the other hand I understand it. He will have done all the testing. He will have had the best preparation," he added.
The bright side is that an agreement between Mercedes-powered Aston Martin and McLaren means that Vandoorne will also be on standby for his former team this year.
"It's not something new or different," Vandoorne insists. "There is a partnership between Aston Martin and McLaren. But in terms of work, I won't specifically do anything different for them.
"I'm there in case they need me at the races where I am present. I'll be in Bahrain for the start of the championship and then in Jeddah and Melbourne.
"There's also my reserve role in WEC with Peugeot," he added. "I hope to have the opportunity to race and also be at the start at Le Mans again."