Coach Nathan Buckley says Collingwood are searching for answers after Darcy Moore and Jamie Elliott both reinjured their troublesome hamstrings in a rough day for the Magpies.
Moore could face an extended stint on the sidelines after going down in just his second game back from a month on the AFL sidelines as Collingwood went down by 21 points to Geelong on Sunday at the MCG.
The 22-year-old pulled up sore after taking a chest mark early in the second term and played no further part in the game.
Collingwood were reduced to two players on the interchange bench when Tom Phillips was concussed early in the third quarter.
Phillips managed to soccer through his second goal while being tackled by Zach Tuohy but copped an inadvertent knee to the head from teammate Chris Mayne on the way down.
Tuohy's hard tackle also drove Phillips' head into the turf and is certain to attract match review scrutiny.
It continued a rough day for the Magpies on the injury front with Elliott earlier suffering a flare-up of a pre-existing hamstring issue in his VFL comeback match.
He and Moore will undergo scans this week, joining an injury list that already includes Tyson Goldsack (knee), James Aish (knee), Josh Smith (hamstring) and Ben Reid (Achilles).
Skipper Scott Pendlebury (ankle) is expected to be available to face St Kilda next week but Buckley says the growing injury toll is becoming a concern for the 11th-placed Magpies.
"Clearly Jamie today and Darcy today are issues for us," Buckley said.
"Rest assured, we're not sweeping them under the carpet. We've got to find the answer to it. We want access to our best players more often.
"We're not sitting on our hands just not assessing whether we can do things better or what the mechanisms might be.
"It is significant. We looked it as a group about three weeks ago and we'll have another look now. We've got to keep providing the best opportunity for players, we've got to keep getting the rehab right so we can get players back and fit and standing up to the competition."
Buckley noted that the Magpies' schedule - having played four games in 20 days - had been challenging, and the Pies have a six-day break before taking on St Kilda at Etihad Stadium next Saturday.