Brett Lee could be left out of Australia's squad for the Ashes against England in July with his recovery being rather slow.

According to a report in the 'Herald Sun' quoting sources, Aussie speed merchant is currently only 70 per cent fit after undergoing foot and ankle surgery in January.

"High-placed Australian sources insist Lee is behind schedule in his recovery from foot and ankle surgery, and it would not be the shock of the century if he was overlooked for the Ashes," the newspaper said.

Lee was picked for the ongoing one-day series against Pakistan but the slow pace of his recovery meant that the 32-year-old had to be replaced at the last moment.

Selectors, who will pick the Ashes squad next month, feel it would be too big a risk to take an untested Lee to Ashes.

"Australian selection boss Andrew Hilditch had wanted Lee on deck for Australia's one-day series against Pakistan, which started last night in Dubai, to assess his form and fitness before the marquee tour of England," the report said.

Lee is currently in South Africa undergoing rehabilitation and training with his Indian Premier League team Kings Punjab XI.