Pakistan skipper Inzamam-ul-Haq said fast bowler Shoaib Akhtar's fitness was a cause of worry and his comeback should not be rushed for the important England tour as the express fast bowler was an asset to the team.

"I would be lying to myself if I say that I am not worried about the fitness of Shoaib Akhtar for the England tour. But at this stage, I would not like to speculate on whether he would miss the tour with the latest injury," Inzamam said from Lahore.

Akhtar, who underwent knee surgery in Australia in February, has reportedly suffered an ankle twist and has not been attending the training camp since its resumption on May 25.

Akhtar was also absent on Sunady when the other 18 probables, including the skipper, attended the camp in Lahore.

"One thing is for sure and that we will not rush his comeback, if we have slightest doubts (on his fitness). He is an asset and needs to be handled very carefully. We don't want to blow away his future cricket with one silly mistake.

"It's a difficcult situation for Shoaib and the team," Inzamam said.

Akhtar has been plagued by a series of career-threatning injuries since making his debut nine years ago and he has missed more tours than he has played, including the tours of India and the West Indies.

But the Rawalpindi express has fought those grim phases and bounced back with flying colours everytime.