The Brumbies' and incumbent Australian No.10 was twisted in a seemingly accidental off-the-ball play while trying to repel a Force attack on his goal line in the 20th minute of Saturday night's derby.
It was initially unclear if Lolesio had suffered a back, hip or leg injury in the incident.
But Stan Sport's sideline commentator and former Wallabies star Cameron Shepherd said Lolesio had sustained a spinal injury.
"We don't want to speculate too much at the moment because there's a lot of scans and a lot of checks that need to be done," Shepherd said.
"But the one small bit of good news is that he is moving his arms and legs.
"They have confirmed it is a spinal injury. At the moment, we just don't understand the severity.
"But, fingers crossed, moving his arms and legs is obviously a very, very good sign."
Lolesio's injury comes almost exactly 24 hours after fellow Wallabies star Joseph-Aukuso Suaalii was escorted off the field on a medicab and in a neck brace during another Australian derby between his NSW Waratahs and the Queensland Reds in Sydney.
Suaalii was knocked out after copping an accidental knee to the head from his Waratahs and Wallabies teammate Andrew Kellaway.
Waratahs coach Dan McKellar said post-match Suaalii went home with his parents in a "groggy" concussed state.
Concerned Wallabies coach Joe Schmidt was watching on at Allianz Stadium.
While Lolesio will most likely be overlooked for Test selection in 2025 after opting to move to Japan at season's end, his injury is another potential huge blow for Schmidt ahead of the looming arrival of the British and Irish Lions for a three-Test series this winter.Â
