Wes Harding and Chiedozie Ogbene missed the 3-1 win over Burton Albion but both are expected to return at the weekend, unlike Miller, who reported a sore groin.
"Mickel isn't great so I can't see him being involved this weekend, but Wes and Cheo are fine," said Warne.
"Cheo was more precautionary, really. I've just got to try and manage certain players but he's trained all week and Wes has trained all week."
Rotherham were badly hit by Covid-19 and the new Omicrom variant is sweeping the country, with football far from immune.
"I am concerned," he admitted. "I have had a couple of members of staff go down and as soon as it gets into the building you start panicking.
"Yesterday (Wednesday) was a day away from training but I got a call and I thought, 'Oh no.' I answered and just said 'Tell me the bad news.'
"Fortunately today it doesn't seem like any players are symptomatic and there doesn't seem to be any drama but I'm panicking I'll get up Saturday morning to a text on my phone from the staff group saying two or three players aren't feeling good.
"I'm not terrified but I am pretty anxious about it, because it seems like it's going through places pretty quickly."