A broken right thumb has added to the doubts over Brett Lee's comeback at the World Twenty20 in the Caribbean. Lee suffered the latest injury playing for Kings XI Punjab on Friday but Tim Nielsen, the Australia coach, is hopeful Lee will be part of the squad for the side's entry into the competition early next month.

Lee has just returned from elbow surgery and has not taken a wicket in four IPL games, increasing the concerns over his ability to return to top-level action. The matches in India are his only appearances since undergoing surgery in December.

''All we can do is wait and see how it reacts over the next four or five days before we have our camp and head off to the West Indies," Nielsen told the Age. "Hopefully it will heal, and the scans and things he's having at the moment will show exactly the nature of the damage and what the likelihood of him playing is."

Lee is not being told to come home from India for treatment and Nielsen said there was a possibility he could appear in Punjab's final game of the competition. Last week Lee was given a Cricket Australia contract to secure his short-form future after he retired from Tests earlier in the year to prolong his career.

"I was pleased they selected him and showed the support that he was looking for and we were hoping for," Nielsen said. "We've just got to hope now that this knock on his thumb clears itself up and we can go from there.''

Lee's agent, Neil Maxwell, feels the fast bowler shouldn't rush his comeback. ''Whilst it would be wonderful for him to be able to play in it, I don't think the Twenty20 World Cup is the be-all and end-all," Maxwell told the same paper. "Brett has constantly rushed to get back into things because of timing, and whenever he has had a good break he's come back firing on eight cylinders. I'd rather him be at 100% when he plays for his country.''

Australia go to the World Twenty20 desperate to improve on their first-round exit in last year's event in England. Nielsen has used Michael Sholly, a club coach in Victoria, to act as a scout on opposition players during the IPL.

''We've been playing so much that it was difficult for us to keep an eye on things in the IPL while we were in New Zealand,'' Nielsen said. ''It was a good chance to broaden a role we already had and be a bit more specific towards Twenty20 cricket. It's another piece in the puzzle.''

Matthew Mott, the New South Wales coach, will travel with the squad as an assistant to Nielsen during the event. Australia's opening game of the tournament is against Pakistan in St Lucia on May 2.