David Warner admits he remains nervous about the restrictive nature of his groin injury.
Warner was rushed back for Australia's third Test against India, conceding before the game started that he was unlikely to be fully fit.
The aggressive opener had spent almost six weeks on the sidelines after his setback during an ODI at the SCG.
The 34-year-old Warner has exhibited obvious signs of discomfort during the SCG Test, especially while batting on day one.
Warner's trademark explosiveness in the field has been missing, although he claimed a key catch to dismiss Rishabh Pant during India's first innings.
There is a three-day break between the third and fourth Tests, meaning the former vice-captain will have limited time to do rehab work on his injury.
"I am (nervous) and I was. It might have been a bit of different circumstances if we were 2-0 up," Warner said.
"When you're doing a fitness test at training, it's quite easy to get through that.
"But once you're out there it is a different intensity ... playing the actual game live is where you get nervous.
"I'm trying to sprint as hard as I can.
"It might look like I'm on a treadmill but it's quite difficult, I'm hoping I can get through this."
Warner embraced cryotherapy, blood injections and other treatments in an attempt to fast track his recovery.
Australia's new opening paring of Warner and Will Pucovski produced partnerships of six and 16 runs in Sydney.
Pucovski, who debuted at age 22 and only started opening the batting this season for Victoria, scored a pressure-laden 62 in Australia's first innings.
"He looks like he's at home," Warner told SEN.
"He's obviously scored a lot of runs in Shield cricket.
"His temperament is awesome ... he's got a bright future ahead."