Sebastian Vettel may have had a shot at replacing Alex Albon for 2021 if he had not signed up with Aston Martin.

That is the claim of Dr Helmut Marko, who advised the quadruple world champion to take 2021 off rather than quickly sign for another team in the wake of his Ferrari ousting.

"It was clear to me that fundamental things would change in the driver market in 2022," Marko told f1-insider.com. "For example, I was sure there would be a vacancy at Mercedes - but not only there."

Immediately after the 2020 season, Red Bull concluded that Albon needed to be replaced at Red Bull to give Max Verstappen a tougher challenger. With a dearth of appropriate talents in-house, Marko appointed Sergio Perez.

"We didn't have anyone eligible for the second seat for our goal of becoming world champion," he confirmed to motorsport-total.com. "So we chose Perez."

Marko insists there is "no shame" in looking outside the Red Bull talent pool, but revealed that his former protege Vettel might have been an option if he was still on the market.

"When Ferrari gave him notice, there was no space for us for 2021," he said. "At the time, we assumed that Albon would develop positively and be able to drive in 2021 as well. I said that to Sebastian.

"Unfortunately we were wrong, and when we had to act Sebastian was no longer on the list because of his long-term commitment to Aston Martin."

However, former F1 team boss Eddie Jordan says he would not have signed Vettel to either team - even if he was in charge at Aston Martin.

"I like Sebastian a lot, but I think Aston Martin made a mistake in signing him," he told Auto Bild. "His last two years against Leclerc at Ferrari were pathetic."