Better news for the Owls arrives with the fact that Harlee Dean, Josh Windass and Nathaniel Mendez-Laing could be involved in the game against Kent and a decision on their involvement will be made after the club's final training session before the game on Friday.
Moore said: "It's a little too early with Gibson and Palmer, we will know more later in the week. They are probably not available and Ciaran Brennan picked up a little knock in the under-23s and we are assessing him at the moment.
Dean and Windass have been back in training this week and are fine and looking good. We will make a decision tomorrow as to whether they will be in the squad. If they aren't, we "definitely know they will ready, fit and available for the Cheltenham game providing we don't get any knockbacks
"Mendez is very much in the same position. We feel all three of them have come off the training ground today and are looking good and have increased their workload. We are really pleased with their progress."
Wednesday endured frustration after being pegged back in their midweek draw with Accrington, which prevented them from moving into the play-off positions in League One.
One positive point was the sight of key defender Dominic Iorfa make his first start since late October following two substitute appearances following his return from a hip injury.
Moore added: "We are really pleased to have Dom back in there. At this stage of the season, it is a massive, massive plus for us and I am really pleased for him. He is another one who has got through a lot of work over the months and it has been a hard road to get back.
"There was no greater sight than to see him start the other night and we saw signs of Dom that he was back to his old self and stepping in and moving up the pitch with the ball and defensively, he was really good as well. He will just get stronger."