Billings, a high draft pick who has had an extensive history of soft-tissue ailments, has recently been recovering from a troublesome hamstring issue.
The run-and-gunning Jones, meanwhile, faces a fitness test for a quad concern he's been nursing, with the expectation also being that he should be able to play this weekend.
Finally, McKenzie, who was in the midst of an impressive 2022 campaign before injury cruelly interrupted, has not played competitively in 12 months and is rehabilitating a plaguing calf injury.
St Kilda acting football boss David Misson on Tuesday expressed pleasure at being able to oversee the imminent returns of the three key Saints contributors.
"Seeing Jack, Zak, and particularly Dan back on the park will be really pleasing and a credit to the hard work of the athletes and our rehabilitation staff," Misson told saints.com.au.
"Working through injuries is taxing and requires a lot of commitment, so, all going to plan, to see that rewarded is great."
Barring any setbacks, all three Saints are expected to suit up for St Kilda's VFL affiliate, Sandringham, when it plays the Brisbane Lions reserves at Trevor Barker Beach Oval on Saturday.
Meantime, key forward Tim Membrey has received an unfortunate six-to-eight-week setback as a knee ailment continues to plague his 2023 campaign.
Membrey, who has also suffered a concussion this season, underwent surgery on his knee during the pre-season period and has played a total of four senior games this year.
Despite the disappointing nature of the timeline, though, senior coach Ross Lyon claimed the situation is "nothing significant" and remained generally upbeat discussing Membrey.
"It's nothing significant. We probably pushed his return a little bit so we've decided to give him a training block of about six to eight weeks," Lyon said during a Wednesday press conference at Saints headquarters.
"He had a little bit of treatment on it last week, get the strength the run and get his confidence back up as a leader of the club.
"He just hasn't been comfortable and confident … and you've got to take the feedback (about what players feel about themselves). He could train and play, but he just doesn't feel it's as strong as it should be.
The Saints are preparing for a season-defining clash with the Lions at Marvel Stadium on Friday night, before travelling to play the struggling West Coast Eagles in Round 16.