Michael Schumacher's brother has added another voice to claims the 41-year-old German might not match the pace of the sister Mercedes car this weekend in Bahrain.
As the racing world gears up for the return to formula one of the seven time world champion, his manager Willi Weber warned this week that Schumacher does not enjoy the W01's tendency to understeer.
And team boss Ross Brawn said: "Nico (Rosberg) has felt a little better in the car (than Schumacher) in his test days."
Ralf Schumacher told Germany's Bild newspaper: "I've heard that Nico is getting along with the car perhaps a little better than my brother. But Michael is working.
"He does not like understeering cars, unlike some other drivers, such as Button, for example, who worked with the team last year," he added.