Melbourne expect superstar Wallabies prop Taniela Tupou to hit the ground running, with their new recruit to start training with the Super Rugby Pacific club early next month.
Signed from Queensland, Tupou will lead a beefed-up pack alongside Test forward Lukhan Salakaia-Loto, who spent last season playing for UK club Northampton.
One-Test All Black midfielder Matt Proctor, England-capped halfback Jack Maunder and Reds utilty back Filipo Daugunu are also moving to Melbourne, with all Super sides unveiling their squads on Thursday.
The Wallabies' World Cup campaign was dealt a massive blow when Tupou suffered a hamstring injury, which saw him miss crucial pool games.
But the 27-year-old was able to turn out for the Barbarians invitational team against Wales last weekend, and Melbourne coach Kevin Foote said he would be available to train on December 4, when the representative players were due back.
The Rebels now have Test forwards Rob Leota, Pone Fa'amausili, Josh Kemeny and Jordan Uelese all up for selection.
"Taniela's been really good - our medical team have been in touch with all the Wallabies player to support them," Foote told AAP.
"He comes in on December 4, so we get the World Cup guys pretty early.
"The scrum is pretty exciting for us and it's smart recruitment."
Former Reds backrower/lock Salakaia-Loto, who started training with the Rebels after missing selection for the France tournament, has already made an impression.
"Lukhan is a massive guy - he's 130 kilograms and he's a no-nonsense guy," Foote said.
"He's come back to Australia and he really wants to win something, so I think the timing of us getting him is pretty awesome."
Among other squad changes, incoming Queensland coach Les Kiss has added All Blacks pairing Alex Hodgman and Jeffery Toomaga-Allen in one of his few big plays to offset the loss of Tupou.
Teenager Frankie Goldsbrough - one of Queensland's most sought-after talents - has also been elevated to the squad.
Experts say Goldsbrough is a realistic chance of joining the likes of Jordan Petaia, Ben Tune and Daniel Herbert as an 18-year-old Super Rugby debutant.
The NSW Waratahs have lost World Cup playmaker Ben Donaldson to the Western Force, and retired former captain Michael Hooper.
Miles Amatosero is set to make his mark, with the 21-year-old second-rower, who stands more than 200cm and weighs 125kg, returning to Sydney after a stint in France.
The ACT Brumbies, who were Australia's best-performing team in 2023, have remained settled apart from the departure of halfback Nic White to the Western Force and Pete Samu to France.
Skipper Allan Alaalatoa is expected to miss the opening rounds as he recovers from an achilles injury.
As well as luring Wallabies halves Donaldson and White to the west, the Force have also recruited former All Black Atu Moli and Reds prop Harry Hoopert to bolster their front row, while backrower Will Harris has joined from the Waratahs.
