Formula 1 legend Alain Prost believes Sebastian Vettel's driving has been affected by the widespread rumours surrounding his future in F1.
Vettel is three places and exactly 100 points behind championship leader and long-term rival Lewis Hamilton at the halfway stage of a 2019 season that began with both the German and Ferrari pegged as title favourites.
However, the SF90 has not proven itself in race trim and Vettel's efforts have been pockmarked with the continuation of errors that saw his title challenge against Hamilton last year go up in smoke.
Vettel's future has become a subject of intense scrutiny, after his lambasting of modern F1 in the aftermath of having victory in Canada swiped by the stewards prompted suggestions he could be ready to quit the sport.
The 32-year-old insists he will be around until the end of next season at least, but evidence of waning powers at the wheel were on show at the British GP last weekend when he clumsily rear-ended Max Verstappen, possibly costing both a podium.
"His incident [with Verstappen at Silverstone] is a lack of judgement on his part," Prost told Canal Plus.
"We see that he is not completely at his best, he has just been overtaken, and tries to retake his position just after that.
"It is still a manoeuvre that is a little difficult, a little daring.
"This may be due to a lack of concentration, motivation, judgement. That's it. Overall, it's not great.
"In addition, there is the pressure of whether he will stop or not [retire at the end of the season], rumours left and right [about his future in F1]. Very sincerely, it must be a very complicated time to live for him."