Any depletion of Glenn McGrath's partnership with Shane Warne will diminish Australia's attack, according to Ian Chappell © Getty Images

Geoff Lawson and Ian Chappell have cast doubt over the future of Glenn McGrath after he was attacked by England's opening batsmen during the Champions Trophy. McGrath, 36, gave up 27 runs in his first four overs against Ian Bell and Andrew Strauss and his slow return from a lengthy lay-off is causing concern ahead of the Ashes.

"We don't doubt his intensity and his discipline, just whether his ageing body can still perform at the top level," Lawson said in The Australian. "He'll certainly play in the first couple of Test matches at the very least and I don't think the Poms will start running at him in a Test match. When the pressure is on at the Gabba it will be a bit different to a one-day game at Jaipur."

Lawson said McGrath was "entitled to a bit of leeway" but questioned the reasons behind him playing in the Champions Trophy when he could have been bowling for New South Wales. "If you got a few four-day games under your belt, it might have been the way to go," he said. "The proof of the pudding is going to be in the first couple of Tests. You wouldn't write him off going out in Brisbane and knocking them over on the first day.

"But when you get to that age, every time you bowl a bad spell people start casting aspersions. This is just a function of getting old. There is going to be an end but when is the end going to come? It's a pretty natural thing to talk about."

Chappell said in his English newspaper column it would be a concern for Australia if McGrath "can't find that extra bit of pace and nip" during the Ashes. "The foundation for Australia's great success in the last decade has revolved around the extraordinary combination of McGrath and his running mate Shane Warne," he wrote. "Any depletion of that partnership will diminish the attack."

He was also not convinced by the bowling of Shane Watson, who collected 3 for 16 in the six-wicket win over England. "Shane Watson has got a long way to go with his bowling before he is in the allrounder class for Test cricket," Chappell said. "Every time Watson claims a victim, Australian players converge and the congratulatory ceremony leads you to assume he's performed a minor miracle and dismissed Sachin Tendulkar and Brian Lara with the same delivery."

However, Lawson was pleased with Watson's display. "Watson is always going to be good against left-handers," Lawson said. "He hardly gets the ball to go away against right-handers but England have a few left-handers, so that's quite handy."