Melbourne Rebels halfback Nick Phipps, NSW Waratahs lock Kane Douglas and Western Force loose forward Ben McCalman were called up after second row Sitaleki Timani, in-form back row Scott Higginbotham and winger Digby Ioane dropped out injured.
Higginbotham left the field with a sore shoulder during his side's Super Rugby loss to the Queensland Reds on Saturday, but the Melbourne Rebel has not ruled out taking part in the tests that start later this month.
Timani picked up a broken thumb as the New South Wales Waratahs lost to the Canterbury Crusaders on Friday and will undergo a scan to determine whether or not he will feature in the three-test series.
Despite continuing rehabilitation for a cartilage issue in his left knee, Reds back Ioane will still join up with the squad, who begin work in Sydney on Sunday.
"Digby is unable to train. His focus is on getting his knee right, which is why we've chosen to bring him in anyway, so our medical staff can oversee the process," Wallabies coach Deans said in a statement.
McCalman was expected to line-up for the Force against the Lions in Perth on Wednesday but his first Wallabies call-up in a year means he will sit out the midweek game.
Phipps is the second scrumhalf named in the squad and gets the nod ahead of Nic White of the ACT Brumbies as the deputy for first choice Will Genia.
"I guess, like every other player in the country, I'm desperate to have a crack at the Lions," Phipps said in a statement.
"It's a once in a lifetime opportunity, one that a lot of players don't get."
Despite his injury, Higginbotham was still optimistic of playing some part in the series following a check-up by leading sports surgeon Peter Myers.
"Hearing from Peter Myers, he thinks I can definitely play with it - I'll see how I go," Higginbotham said.
"Hopefully I'll be right to train and push on for selection for the Lions.
"The doc said I could definitely play with it if I don't need surgery - I'll push on and strengthen it."
Deans named a preliminary squad last month and will add six more on June 11 ahead of the first test in Brisbane on June 22 but the rigours of the physical Super Rugby competition have taking its toll.
First choice openside flanker David Pocock will miss the series with George Smith, a likely replacement, struggling with a knee problem picked up last month. Hooker Tatafu Polota-Nau was left out of the squad because of a broken arm.
Media reports in Australia suggest back Kurtley Beale, who is undergoing treatment for alcohol-related problems in a Sydney clinic, will also be invited to train with the squad after a runout for his club Randwick on Saturday.
The Lions thrashed the Barbarians 59-8 in Hong Kong on Saturday and arrive in Australia on Monday to continue preparations for the test series.
- Sports & Recreation
- Scott Higginbotham
- Digby Ioane
- Sitaleki Timani