Australia fast bowler Glenn McGrath has cast doubts over Pakistan's ability to improve sufficiently to be competitive in this week's second Test after their 491-run thrashing in Perth.

McGrath also disagreed with suggestions Australia's dominance was bad for the game, saying it would only fuel the desire of other teams such as England to match captain Ricky Ponting's side.

"Nobody wants to come and see a two-day Test. You don't want it to be too easy," McGrath told reporters in Melbourne on Thursday ahead of Sunday's second Test.

"When we play as well as we can, it's tough for any team, let alone a young team like Pakistan.

"I guess if any team can do it, Pakistan can. One day they can play pretty ordinarily and another time they can bounce back and play out of their skins."

The 34-year-old McGrath has returned to the top of the bowling rankings in Test cricket after taking a career-best eight for 24 in Pakistan's second innings of 72 to lead Australia to victory on Sunday's fourth day of play.

"A five-day Test is a bit of a rarity these days," said McGrath, who is Test cricket's fourth-leading wicket-taker with 472 victims in 104 matches.

TRUE TEST

"Who knows? We might get a bit more time to recover and prepare for Sydney (third Test January 2-6).

"Here will be the true test. It won't be quite as quick and as bouncy.

"Hopefully guys like Inzamam-ul-Haq and Yousuf Youhana can do the business for them. They are senior players and they have to help the young guys out.

"If they [Pakistan] can work on their batting and get that to click, they shouldn't be too bad. You always like a good challenge.

"Warnie [Shane Warne] wants to bowl them out for 50. We'll see what happens there."

McGrath said he strongly disagreed with the theory that Australia's dominance, including nine wins and three draws from 13 Tests in 2004, was bad for the game.

"You look at the West Indies side of the mid-eighties, how strong and dominant they were," McGrath said.

"Yet every other team was striving to get up there and equal them and that was seen as a good thing.

"But when Australia is so dominant, everyone says it's a bad thing for world cricket, which I don't think is so.

"You see England at the moment, eight wins in a row. They are a team on the improve and hopefully other teams can do the same thing."