Former sprint king Robbie McEwen says Mark Cavendish appears "a bit flat" on this year's Tour and is just "not on his game at all".
The Australian's underwhelming review came after the Manxman was passed and outsprinted by Marcel Kittel yet again at the end of Thursday's Stage 12.
It was the young German's third stage win of the Tour for Argos-Shimano.
By contrast, Cavendish has had only one success - Stage 5 - for his 24th career win and went into Stage 13 trailing Peter Sagan by 96 points in the race for the green jersey.
McEwen, a three-time green jersey winner, said Cavendish appeared to be paying the price for his stellar performances in the Tour of Italy, where he won a handful of stages.
"I don't think he's on top form," McEwen told ITV Sport. "He's found it really difficult to recover sufficiently for the Tour de France."
The Brisbane-born rider said Cav is certainly riding out of character with Omega Pharma-Quick-Step.
"I have almost never seen him ever blow up in a sprint," McEwen added. "And I've seen it three times in a week."
Cavendish's unhappy Tour has seen him battle illness early on and face criticism in France for his collision with Dutchman Tom Veelers at the end of Stage 10.
A day later, a swig of a bottle thrown at him during the 33km time trial turned out to be urine.