Yet the Japanese F1 star is under contract with AlphaTauri, Red Bull's sister team, and Marko has now made it clear that Aston Martin would have to come to them directly if they were to have any chance in tempting Tsunoda away from the Faenza-based outfit.
"Tsunoda is under contract with us," he told F1 Insider.
"If Aston Martin should express interest in him as early as next year, they would first have to come to an agreement with us."
Marko therefore appears to have poured cold water over the idea of Tsunoda replacing Stroll at Aston Martin. Yet speculation surrounding the Canadian's future at the team will only persist should his performance levels fail to improve in the five remaining races of the season.
Stroll will be eager to prove himself at the upcoming United States Grand Prix, as F1 heads to Austin, Texas this weekend.
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