Andrew Flintoff is struggling to be fit for next month's World Twenty20, the England all-rounder said on Saturday.
Flintoff suffered a knee injury playing in the Indian Premier League (IPL) last month and underwent keyhole surgery which he hoped would give him a good chance of playing in the tournament in England.
"I saw the specialist on Tuesday and he was obviously pretty cautious about it," Flintoff told Sky Sports in an interview.
"It's got to be right. I've been named in the Twenty20 squad but the rehab is going to have to go extremely well and I'm probably going to have to be a bit lucky as well."
Flintoff said he was still at least a week away from trying to run.
"One of the things we've got to be careful about is swelling, which is why we're constantly icing and monitoring it," he said.
The World Twenty20 begins on June 5 at Lord's.
Flintoff, 31, is still optimistic about his chances of playing in the Ashes series against Australia starting in July.
"Having experienced the Ashes before, I desperately want to play in it again," he said. "To be involved once more is motivating enough."