Kevin Pietersen has questioned whether Alastair Cook still has the stomach for an Ashes battle after struggling in the opening two Tests with Australia.
Cook has only scored 62 runs in the series so far, his highest score just 37 in the first innings in Adelaide, a long way from his heroics in 2010-11 when he averaged 127.66 across the series.
He is not alone struggling with the bat this time around as England travel to Perth already 2-0 down in the five-match series.
The third Test at the WACA will be Cook's 150th cap and while Pietersen believes his former team-mate can turn things around, he is worried the desire to do so is waning.
"It looks like Cook is not very interested," Pietersen said, as quoted by ESPNcricinfo.
"Just the way that he's got out, the manner of his dismissals and also the way he's walked off the field once he's got out.
"That's the sign of a bloke who goes, 'You know what? Maybe my time is up.' But he's also quite resilient so can he turn it around.
"He's a wonderful player and has been for England for a hell of a long time. This will be his 150th Test match, so you never know.
"He might be able to put up a performance in his 150th Test match, which gives them a lot of energy and excitement going into the WACA. He's got a Test hundred at the WACA before. But who knows?
"That fire burns in your belly for a number of years and then eventually it starts to go out. I had spotted it before the series and there's certainly no signs at the moment to prove there's any fire in Cook's belly."