Former F1 driver Jolyon Palmer says Sebastian Vettel's recurrent mistakes are "unacceptable" for a four-time world champion on whom the pressure is clearly mounting.
Vettel threw away a podium finish last weekend in Bahrain when a wheel-to-wheel battle with Lewis Hamilton during the race ended with the Ferrari driver spinning his way out of contention.
The mishap mirrored a clumsy behavior showcased by Vettel last season on several occasions when the four-time world champion appeared to have the upper hand over Hamilton only for his mistakes to ruin his efforts.
Four spins in the last ten races have inevitably led to questions about Vettel's status and his ability to withstand pressure says Palmer.
"Vettel's spin in the race in Bahrain was amateur," wrote the former Renault F1 driver in his BBC column.
"The spin was different to his three at the back end of last year because this one was on the exit of the corner, rather than on the entry or at the apex with a car squeezing him from the outside.
"But the reason for it seems to be the same - panic in the heat of battle.
"Conditions were tough. High winds play havoc with the balance of an F1 car. They make them so difficult and unpredictable to drive because the cars rely on having the perfect airflow to make the downforce work.
"On top of that, in Bahrain the desert wind can blow sand onto the track. So not only is fluctuating downforce an issue but the track grip can reduce as well.
"But this is a weak excuse for a spin of that simplicity.
"If a backmarker rookie had spun in the manner Vettel did, they would have been a laughing stock after the race. For a four-time world champion to do so should be unthinkable.
"Mistakes happen, but this is now four spins in Vettel's past 10 races going back to Monza last year. That's clearly an unacceptable trend for a championship challenger."
Reversing that trend will be Vettel's only salvation insists Palmer, with the Ferrari driver absolutely avoiding any more mistakes this season.
"He simply must get his head down and deliver consistently and not spin again for a very long time - all season, basically, if he wants to be champion by the final race in Abu Dhabi on 1 December," added the Brit.
"That's easier said than done, because next time Vettel heads into wheel-to-wheel combat, with a car on his outside, he is sure to be wary of his mistakes.
"But if he's too cautious as a result he will be dead meat in the competitive front order.
"As soon as you are seen as a soft touch, people will be even more elbows out, lunge at you from further back and get even more aggressive with you, taking risks they perhaps wouldn't otherwise."