The rampaging Queensland Reds lock, as well as Brumbies second-rower and 38-Test veteran Nick Frost, were both missing from Friday's 37-man squad named ahead of games against Ireland, France and Italy next month.
Instead Schmidt, who will hand coaching duties to Les Kiss after that trio of Tests, has called up rookie locks Lachlan Shaw and Miles Amatosero alongside Josh Canham and Jeremy Williams.
With the hulking Will Skelton out injured it was assumed Salakaia-Loto would fill the role of enforcer, with the likes of James Horwill last month backing the 29-year-old to transfer his barnstorming Super Rugby Pacific form to the Test arena.
But Schmidt, who consulted heavily with Kiss on this squad, wants to see improvements and has given the 45-Test talent a task ahead of next year's home World Cup.
"Incredible athlete, had some really good moments in Super Rugby, it was just stringing consecutive moments together," he said in Sydney on Friday.
"We're looking for him to have a block to get into the best physical shape to contribute to the team.
"We need fast jumping locks. We know he's got that speed but isn't quite where we'd like him to be at the moment.
"We've got Ireland in two weeks (on July 4) … then in 16, 17 months time it's going to be massive here in Australia."
Left out of Schmidt's Wallabies squad for the British and Irish Lions tour, Salakaia-Loto unleashed brilliant cameos for the Reds, Anzac XV and First Nations Pasifika XV against the tourists, attempting to force his way in.
Test caps eventually came in losses to Argentina and New Zealand before he was injured inside 10 minutes against Japan and featured just once more on the European tour.
The coach said 23-year-old Brisbane junior Shaw's workrate impressed him and wants to see Amatosero, who spent three years at Clermont Auvergne in France before returning home to Sydney with the Waratahs, at the next level.
"He's the right size and shape," Schmidt said of 24-year-old Amatosero.
"For them to get a bit of experience in a window now allows Les a broader selection group."
Brumbies playmaker Declan Meredith, who played his junior football in Cairns, is the third uncapped member of the squad.
Veteran prop James Slipper, after retiring last November, could surpass All Blacks great Sam Whitelock as rugby's second most-capped player in history after answering an SOS call from coach Joe Schmidt.
Fellow loosehead Angus Bell also features following a season-long sabbatical with Ulster in Ireland while French-based tighthead Taniela Tupou could play against Ireland if his Racing 92 outfit loses their Top 14 semi-final this weekend.
"It cost me a coffee," Schmidt said of luring Slipper back at 37.
"There's an old dog … great to lean on and he's a known quantity and leader in the group, which we lacked a bit during last season (after injuries hit)."
Reds centre Hunter Paisami was included despite missing the late stages of the season with a knee injury and could be fit to face Ireland, according to Schmidt.Queensland fullback Jock Campbell's form has him within reach of a Wallabies recall, having last played for his country back in 2022.Scrumhalf Tate McDermott and fullback Tom Wright, who will compete with Campbell for the No.15 jersey, also return having missed the back end of last year's campaign with injury.
Kalani Thomas and Ryan Lonergan are the other scrumhalfs in the squad while Carter Gordon and Ben Donaldson will jostle with Meredith for the No.10 jersey.
UK-based pair Len Ikitau and Tom Hooper, like Tupou have also been selected, with all three set to feature in domestic finals matches this weekend and Schmidt said they could still face Ireland.
"They're absolutely flying," he said.
After facing Ireland, the Wallabies travel to Brisbane to play France at Suncorp Stadium on July 11, before taking on Italy in Perth the following Saturday.
Veteran half Jake Gordon, the code-hopping Zac Lomax, flyhalf Tom Lynagh and former captain Skelton were among a raft of big names unavailable through injury.
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