Jamie Elliott will return from the shoulder injury that sidelined him for the last five rounds when we play Fremantle on Sunday.
"It is really exciting (to have him back), Jamie could have missed up to three months," Fly said.
"It's a credit to him and our rehab team to get him back so soon, he's missed five weeks.
"He's a super talent for us and a player we have missed enormously.
"His leadership and his ability to set others up and organise - we have certainly missed that."
Fly said facing third-placed Freo in Perth will be a huge test.
"We are comfortable we will go over there with purpose," he said.
"The dockers will be a great challenge for us but we go over there with great confidence and optimism.
"We're not daunted by any game we play - we trained really well this week and we know our best is really competitive.
"We look at managing their strengths and exploiting weaknesses, we will go about it the same way we do every week."
Mason Cox will play his first AFL game since round five.
"Aiden Begg has given us three games of great learning and he will be much better for the experience," Fly said.
"Mason has been playing above the level in the VFL for the last three weeks.
"He will play mainly ruck and we are looking forward to him putting his best foot forward."