The Pies face a short turnaround this week with a few personnel changes ahead of Thursday night's match against Brisbane.
Brody Mihocek is no longer available after entering health and safety protocols, while small forward Jack Ginnivan will miss his first game this season due to soreness.
"Brody's partner has covid and he's a close contact, so he won't play," Fly told media on Tuesday.
"Jack is a little bit sore so he won't come up (to Brisbane) either.
"We will have to get creative with our forward line but it creates opportunity for a couple of others."
Taylor Adams is expected to play after completing Tuesday's main training session, while Jordan Roughead and Nathan Kreuger are both a chance.
"Coming back from Covid is always a watch and see," Fly said.
"He trained well today and at this point we're anticipating he will play.
"Roughy played in the VFL and it was just about getting some minutes and some confidence in his body.
"He did that so he will be up for selection as well.
"Kreugs trained well, we're hoping to get him through the next 24 hours and get him on the plane."
When asked for his thoughts about naming a side with two talls in Mason Cox and Kreuger, Fly said he's "not sure yet".
"They played well together in Morwell but that's something we will discuss at selection."
On last week's loss to West Coast, Fly was pragmatic.
"Our accuracy didn't help."
"(In the last two rounds) we played teams that shoot the lights out a little bit - credit to West Coast for kicking 14.3.
"Our core business, if you like, we're reasonably happy with and we want to maintain most of what we're doing."
Last time Collingwood faced Brisbane at the Gabba they were handed an 85-point shellacking.
"It's a hard place to play - they have a fortress up there," Fly said.
"This clash is traditionally such a big occasion and played in front of a big audience, I know the Lions will bring their best."
The head coach said Jamie Elliot is in good spirits following surgery to repair his AC joint injury.
"The time frame we're not too sure about, he's optimistic he'll be back sooner," Fly said.
"He will be sorely missed - I love the kid, I coached him when he was a boy here at Collingwood.
"He's such an important part of where we're going."
