He will have a scan on Monday and anything more serious than tightness could sideline him for the remainder of the Swans' flag tilt, with a preliminary final in just under two weeks and the Grand Final a week later.
"I'm not sure how bad (it is), but he seems pretty positive, so fingers crossed that it all goes well for him," said Rhyce Shaw, the Swans’ other dynamic rebounding half-back.
"It doesn't seem too bad, but we won't know anything until that scan tomorrow morning.
"Hopefully he gets back because he's a really important player for us and I certainly want him out there. He's fantastic."
One option for coach John Longmire if Malceski doesn't make it back for the preliminary final is swinging co-captain Jarrad McVeigh into the vacant position, which he dropped back to fill on Saturday.
Shaw, who has suffered his share of injury woes over the past two seasons, tried to lift the spirits of his good mate Malceski after he came off the ground.
"I just said 'keep positive, we'll try and do the best we can and try and get the win so he can get an extra week to recover and hopefully get back for the prelim'," Shaw said on Sunday.
"We're pretty close, so I just got over to him and gave him a bit (of support)."
Shaw, who like Malceski has undergone LARS surgery on a knee, found some form against Fremantle in his third game back from an ankle injury, racking up 23 disposals against the Dockers.
"It was really important to get those two games in before the final, I wasn't playing great footy in those games," Shaw said.
"But I got some form last night and that was the main thing."
Shaw said having a week off was definitely an advantage after such a tough and taxing game.
Meanwhile, Shaw implored dasher Gary Rohan to keep running and chancing his arm despite his error-marred first half in Saturday's qualifying final win over Fremantle.
Speedy Rohan made errors which led to Fremantle's first two goals, and had two wildly inaccurate shots for goal in the second quarter.
Rohan was much more productive in the second half, as he continued to back himself after getting the support of his teammates.
"We just told ‘Gaz’ to run as fast as he can and hope for the best," Shaw joked.
"We want Gaz to break the lines and that's what he's in the team for.
"Those skill mistakes, they will come. I used to make a thousand of those when I was younger, so it doesn't really matter.
"You get over that and you mature as you go along.
"But at the moment we want Gaz to defend and to break the lines and he was doing that.
Hear from Swans senior coach Dean Cox as he addresses the media ahead of Sydney Derby XXXII
07:32
The Heroes of Horsham
Local footy clubs are so important to small communities around the country, so we paid a special visit to those who had an impact on Bloods legend Adam Goodes, and club stalwart, Jake Lloyd
14:47
"Once we step over that white line it's on" - Blakey
Sydney Swans Nick Blakey and GWS Giants Lachie Ash address the media ahead of Round 6 Derby clash at the SCG this Friday.
11:51
Behind the scenes at Gather Round | Inside Sydney 90s edition
Relive our Gather Round win against the Gold Coast Suns at Norwood Oval.
See the latest update on the Sydney Swans squad ahead of our Round 6 match against the GWS GIANTS. This Injury Update, presented by Castlereagh Imaging.
Key Quotes: Nick Blakey, Sydney Derby
Hear from defender Nick Blakey as he discusses the upcoming Sydney Derby in a dual presser with the GIANTS' Lachie Ash.
Rosas Jnr earns Goal of the Year nomination with incredible major
Malcolm's brilliant ball work has earned the forward a Coles AFL Goal of the Year nomination in Round 5.
Heeney polls top coaches votes in Round 5
The Swans enjoyed a clean sweep in the club's Gather Round clash with the Gold Coast Suns, with Isaac Heeney leading the pack.