Jos Verstappen, the father of F1 world champion Max, has criticised Red Bull's strategy at the Monaco GP, insisting valuable points were "thrown away" because they favoured eventual winner Sergio Perez.
Verstappen finished third in Sunday's race as team-mate Perez claimed his first win of the season, with both drivers hailing Red Bull afterwards for outsmarting Ferrari with their pit strategy.
But Jos, who made 107 F1 race starts before retiring in 2003, believes Perez was wrongly prioritised by the team given his son's title lead.
"Red Bull achieved a good result, but at the same time exerted little influence to help Max to the front," Jos wrote in a column on Max's official site.
"That he finished third, he owes to Ferrari's mistake at that second stop of Charles Leclerc.
"Max was not helped by the chosen strategy. It turned completely to Checo's favour. That was disappointing to me, and I would have liked it to be different for the championship leader."
Perez went from third on the grid to first in the Principality after Red Bull, with the Mexican having outqualified Verstappen, opted to pit him first onto intermediates, allowing him to undercut Leclerc and ultimately Sainz. Verstappen would follow him in, although was far behind Sainz on track.
Verstappen has still extended his championship advantage over Leclerc to nine points, but is only 15 ahead of Perez.
"Perez actually won the race because of the earlier pit stop," Jos insisted. "The team can perhaps explain that as a gamble, but they had already seen, with for example Gasly, that the intermediates were the best option at that time.
"I would have liked them to go for Max, but of course I am not entirely objective."
He added: "I think 10 points from Max have been thrown away here. Especially with the two retirements we've had, we need every point. Don't forget that Ferrari currently has a better car, especially in qualifying."
Jos also highlighted Red Bull's car not suiting Max's style.
"Max's third place was very disappointing," he said. "We all saw that it was a difficult weekend for him.
"It starts with the car, which simply doesn't have the characteristics for his driving style yet. Max has far too little grip at the front axle. And especially in Monaco, with all those short corners, you need a car that turns very quickly. That was just hard."