Sebastian Vettel has admitted that Ferrari's much-vaunted Singapore upgrade has helped him.
The German has struggled with the Maranello-made 2019 car this year, to the point that some believe Charles Leclerc is now the number 1.
"With the direction taken by the development of the car, it seems to be better for his style," Marko said.
Vettel does not deny that the new front wing, floor and diffuser have helped him to speed up in comparison to his teammate Leclerc.
"The update that we brought to Singapore helped us," the quadruple world champion told Bild newspaper.
"And maybe it also helped me in areas where I had some problems."