Last Sunday's British Grand Prix saw Sebastian Vettel uncannily bookend what has been a thoroughly rotten year.
Twelve months earlier he snatched a home victory from Lewis Hamilton at the Northamptonshire track, but just two weeks later threw away almost certain victory in his own home race when he went off while leading at Hockenheim.
There followed a number of further mistakes, which derailed his title challenge and have continued into this season, last Sunday's incident with Max Verstappen being the latest example.
"You make mistakes when you are no longer sure of yourself," Marko tells Germany's AutoBild. "It happens in the subconscious.
"Sebastian would have to be in a different environment," he added. "In other words, change team, but I see no way for 2020."
"Sebastian is a very intelligent, sensitive and warm-hearted man," added team manager, Jonathon Wheatley. "You can tell by how loving he is to his wife and his children or the fantastic speech he delivered in honour of Charlie Whiting at Silverstone.
"He's not a tough guy like Michael Schumacher or Fernando Alonso, who were always able to perform. Sebastian is a driver who has to feel unconditional support. He had that with Red Bull. And he probably doesn't have it at Ferrari."
The comments come days after Lewis Hamilton once again gave his moral support to the four-time champion.
"I absolutely believe he'll rebound," said the Briton, "you look at the greats, and he is one of those. He's had a difficult race but he's a four-time world champion, he will recover, he will come back stronger the next race, and that's what great athletes do."