But he is optimistic that the on-loan Tottenham Hotspur forward is not far off a return to action.
Sterling has been sidelined for almost five weeks after suffering a thigh injury - which Moore and the club’s medical team initially thought was a dead leg - in the derby win over Rotherham United last month.
The 20-year-old has since been for scans to check the problem. He seems unlikely to feature at Oxford United this weekend with Moore keen to tread carefully.
“I think we underestimated it,” said Moore.
“When you think of a dead leg you think it’s just a dead leg. So I think we have underestimated it.
“Even when it happened I’ll be honest I thought dead leg, which can be anywhere from four days to two weeks tops.
“But I think with the severity of it we’re just making sure there’s nothing that we’re not detecting or picking up.
“Since he got the injury he’s been away and we’ve nurtured him back, we’ve given him the treatment, he’s returned back to his parent club and he’s had a couple of scans.
“Hopefully he’s slowly getting back into training. It’s one of those where we’ve got to build him up. With Kazaiah his game is about energy, power and speed.
“He’s such an electrifying player that the last thing we want is for him to explode into a burst of speed and for something untoward to happen.
“It’s been a really difficult one because when you think what we could do with his ability it would be wonderful.
“But at the same time we have a duty of care for his health, making sure that when he comes back he stays back.”
Moore would not confirm or deny whether Spurs will have the final say on when the highly-rated Sterling returns to action.
“We’re working together with Spurs,” said Rovers’ boss.
“If it meant him going back to Spurs because it speeds up the recovery process and because of the man power they’ve got there and the equipment then great stuff.
“But he’s nearly there. We’ve just got to make sure that we take every precaution and make sure when he comes back he stays back.
“We missed him two or three weeks and we just thought it was a dead leg. But we’ve checked him out now and hopefully he’ll return soon.
“He’s been there or thereabouts. He came back into training but we’ve taken him back out of training just in case.
“We just don’t want to miss anything. That’s the reason there’s been a lot of confusion with him. Hopefully we’ll know more this week. Could he be involved at the weekend? We’ll wait and see.
“The scans were clear but we’re just double checking one or two things,” he added.
“With both clubs working together I expect we’ll find out what it was. Hopefully it’ll be nothing and it’s a clean bill of health to kick on.”
Sterling has scored one goal in four appearances since arriving at Rovers on a season-long loan.