Derby County boss Billy Davies feels it could be mid-September before Giles Barnes is fit to play.
"Giles is still a number of weeks away as regards fitness," Davies told the Derby Evening Telegraph.
"First we will look to get the all-clear and then try to get him back to full fitness, which will take two or three weeks after that.
"We want to get him 100 per cent right, so he can perform to his best."