CHENNAI: Doubting Thomases have gone hammer and tongs about whether injured Indian left-arm-pacer Zaheer Khan can come back and lead the attack with the same venom after the latest setback in England. The 33-year-old had a surgery on his injured ankle and if legendary Aussie pacer Dennis Lillee is to be believed, Zak will find it very hard to make a full-fledged comeback. "I think Zaheer's injury happened due to stress. If he was 18 years old, his recovery would have been faster. But when a player suffers a fresh injury at 33, he naturally takes more time to get back into action," Lillee, who is in the city overseeing the MRF Pace Foundation conditioning camp, said on Monday. Zaheer is one of Lillee's favourite wards and the Aussie expects a lot more from the Indian pacer. "I'm not a doctor, so it's not possible for me to point out if his international career is all but over," he added. Lillee though was happy for rookie India speedster Varun Aaron, who has been drafted into the Indian ODI side against England. Aaron, a product of MRF, is genuinely quick and has a lot of potential, he feels. "He is a rare talent. I'm extremely happy that Varun has made it to the national squad. He is young and needs some time before he flourishes at the highest level. He came at the MRF Pace Foundation as a 16-year-old boy and we all have put in a lot of effort to groom him. I am confident he would excel against England if given a chance," the Aussie explained. There have been many instances in the past when young pacers have shown great potential, only to fade away after some time due to injury. Aaron, who consistently bowls above 145/kmph, had suffered two stress fractures in his back, "Varun is still very young and his injuries are completely healed. But he should be more careful now and he has to learn how to protect himself despite playing a lot of cricket," he said.