With 39 Test caps, Kellaway will add valuable experience to the Waratahs in their clash with the British and Irish Lions in Sydney on Saturday night at Allianz Stadium.
The match is less than 24 hours before the Wallabies take on Fiji in Newcastle, with Tupou also missing Test selection after the prop was sent back to the Waratahs on Monday.
Speedster Toole will head home to Canberra, with Australia's top-ranked Super Rugby side hosting the tourists on Wednesday, July 9.
Their release leaves Western Force flyers Harry Potter and Dylan Pietsch, who starred against the Lions in Perth in their opening tour match, Queensland's Filipo Daugunu and NSW young gun Max Jorgensen still in winger mix to face Fiji on Sunday.
Joseph-Aukuso Suaalii and Tom Wright are the leading fullback options left in the squad following the departure of Kellaway, with the Test side to be named on Friday.
Wider Wallabies squad members, Tane Edmed, Darby Lancaster and Matt Philip, have returned to bolster the Waratahs while David Feliuai, Lington Ieli, Ryan Lonergan and Rory Scott will re-join the Brumbies.
Brumbies coach Stephen Larkham will be happy to have Toole back in his attack after he posted 11 tries during a stand-out Super season.
The Brumbies became the first state side to ever beat the Lions, claiming a 14-12 victory in 2013.
Larkham said he expected the Lions to be at full-strength for their GIO Stadium given it's 10 days out from the first Test in Brisbane on July 19.
"That's what we're thinking - 10 days out from the first Test we're expecting that they'll put their best team out there, and we'll look to do the same, obviously," Larkham told AAP.
"We know our preparation has been really consistent this year, and we'll try and put another really good week together and get our guys into the game with as much confidence as possible."
