Moore was withdrawn from the Swans round one squad to play Melbourne after sustaining an ankle injury at training.
“Gary Rohan hurt his knee last week and it looks as though he might miss a few weeks, so he is out and Jarred Moore will come back in,” Longmire said.
“Initially the diagnosis (for Jarred) was probably a bit longer but he has played the last two few weeks in our Reserves and played in the midfield a couple of weeks ago and did really well.
“He’s an experienced player for us and helps with our setups and hopefully with the slippery conditions, he’s valuable ground level as well.
“I think the beauty of the first few weeks of the season is that we’ve been able to play Byron Sumner, Alex Johnson and get games into them and give them a little bit of experience, so its increased our depth whilst outher players have been injured and coming back into the team.
“Jarred Moore and Tadhg Kennelly are real quality senior players who we are looking forward to getting back into the team,” he said.
Longmire revealed he had toyed with the idea of adding either Mark Seaby or Mike Pyke to the team to take on the Blues, but said he would back Shane Mumford to shoulder the majority of ruck work again with the help of Jesse White.
"There were some discussions around playing another ruckman,” he said. “At some stage we’re going to have to make that call and decide upon that when the time is fit."
As announced earlier this week, Tadhg Kennelly will make his return to senior football this Friday night, with youngster Alex Johnson sidelined with a hamstring strain.
Sydney Swans team list
B: P.Bevan, T.Richards, R.Shaw
HB: T.Kennelly, H.Grundy, N.Smith
C: C.Bird, K.Jack, M.Mattner
HF: J.Bolton, A.Goodes, D.Hannebery
F: B.McGlynn, S.Reid, R.O'Keefe
Foll: S.Mumford, J.Kennedy, J.McVeigh
Interchange: A.Everitt, L.Jetta, J.Moore, J.White
Emg: L.Johnston, L.Parker, M.Pyke
In: T.Kennelly, J.Moore
Out: G.Rohan (Knee), A.Johnson (Hamstring)