Fyfe underwent minor knee surgery over the summer and is still yet to feature for the Dockers this season.
The 33-year-old strung together three consecutive WAFL practice matches last month as he edged closer to senior selection, but sat out last week due to knee soreness.
The week off did Fyfe the world of good, but it wasn't enough to earn him a recall for Sunday's Gather Round clash with Richmond in Adelaide.
Instead, Fyfe is set to line up in the WAFL for Peel Thunder again against South Fremantle on Saturday.
Despite the emergence of Caleb Serong, Andrew Brayshaw and Hayden Young as A-grade midfielders, Fremantle still think Fyfe offers value to the on-ball brigade.
When asked whether he still considers Fyfe a part of Fremantle's best outfit, Longmuir replied: "Yeah I do. But he's got to be fully fit.
"He's got to be injury free. He's got to be really confident in his body and his game."
Fyfe's availability adds to a selection squeeze at the Dockers despite the club's triple injury blow from last week's 16-point win over the Bulldogs.
Star big man Luke Jackson (hamstring) will miss two to three weeks, Nathan O'Driscoll (ankle) is out for four to six weeks, while Corey Wagner (calf) will miss at least one week.
Ruckman Sean Darcy (ankle/knee) and Young (hamstring) both made a successful return via the WAFL last week and were named in the extended squad, along with Liam Reidy, Sam Switkowski, Oscar McDonald and James Aish.
"That's what we want to create as a football club ... we want a selection squeeze, competition for spots," Longmuir said.
Fremantle's biggest selection call will be whether to play Darcy, who has been injury prone over recent seasons but still looms as a critical part of the club's premiership push.
"Not at all," Longmuir replied when asked if he had doubts about whether Darcy could make it through a full AFL game.
"Clearly he won't be as match fit as he will be in three, four, five games time, but we've got to start somewhere."
If the Dockers opt to give Darcy another run in the WAFL, the task of taking on star Richmond ruckman Toby Nankervis will fall to three-gamer Reidy with back-up from forward Patrick Voss.
Reidy struggled against Melbourne's Max Gawn during a pre-season game and didn't have much impact in the round-one loss to Geelong before getting axed.
