Ledley had to be brought off with a groin injury in the victory over Preston and Gavin Rae, who replaced him shortly after the hour mark, is likely to step in.
Chopra is also a major doubt as the striker is suffering the effects of a stomach upset.
Fellow forward Jay Bothroyd will definitely miss out through suspension after picking up his fifth booking of the season.
Anthony Gerrard was taken off with a cut head against Preston but the defender is unlikely to be ruled out.
A win for Cardiff will take them to within five points of second-placed West Brom.