Kelly had to be withdrawn due to a calf injury in the game against Bristol City, only his second appearance since signing for the Millers in November.
Ward would probably be keen to line-up against the side he played 117 times for, but Redfearn is not interested in forcing players back before they reach full fitness.
He said: “The majority of the lads that have had bumps and knocks are not far off being fit. Whether that’s for Tuesday or for Saturday, I don’t yet know. What I don’t want to do is get them back for one game, 60 minutes, and then lose them for another four or five weeks.
“Both Stephen Kelly and Danny Ward are important to us because they have been part of us playing better recently. If we can get them fit and out there, it would be a big plus for us.”