While the club doesn't have an exact timeline, Dockers coach Justin Longmuir anticipates a five-week stint, at minimum, for Darcy.
Darcy is managing another flare-up of the same calf he strained in January.
Ruled out of the round-six derby, the 27-year-old was building his way through concussion protocols when he hurt his calf in a rehab session.
"We don't have a timeline, so to speak," Longmuir said on Tuesday.
"But it's a very similar injury to what he did in pre-season, and he missed about five weeks with that.
"We're expecting something along those lines."
It is just the latest of hamstring, calf, knee and ankle issues for Darcy, who had played just 44 games across three seasons before this year.
Former Magpies player Mason Cox has been called up in Darcy's absence to partner with star ruckman Luke Jackson, with the Dockers sitting second (6-1) to Sydney on percentage.
Asked if their winning start has given them wiggle room for Darcy's timeline, Longmuir said: "We'll play that by ear as rehab unfolds.
"No player wants to be out of footy for longer than they need.
"There are different ways we can bring him back to AFL readiness.
"Whether that's the WAFL, a little bit less game time to start, instead of another rehab session. We'll look at those sort of things as his rehab progresses."
Longmuir is hopeful Patrick Voss (illness) will be fit to face the 10th-placed Western Bulldogs on Friday, though he admits the key forward is still feeling unwell.
Voss was a late out before their eventual win over Carlton, with Jeremy Sharp kicking two goals as his replacement.
"If 'Vossy' is right, Vossy will come back in," Longmuir said.
"He's here (at training), don't know how much he'll do.
"He did a light run yesterday, but he's still feeling a little bit.
"It's more about making sure he recovers rather than getting him out there and doing it all today."
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