Derby skipper Robbie Savage will lead out the Rams at Wigan on Saturday after recovering from a foot injury.
Jewell, though, concedes Savage has not been at his best since a £1.5million from Blackburn last month due to a number of knocks.
"Sav had a week off from training last week after taking quite a nasty knock on his foot," said Jewell.
"He has had niggle after niggle and he has been playing with the help of injections.
"We are hoping to get him playing pain-free and get him playing somewhere near his potential."