Almost a year on from knee surgery, Australian white-ball captain Aaron Finch says he is finally ready to recapture his hard-hitting best.

The veteran opener has been unable to fire since an operation to repair cartilage in his right knee last August.

He rushed back to play in last year's Twenty20 World Cup when he was well down on fitness.

At 35, Finch's position as skipper has come into question ahead of Australia's World Cup title defence on home soil in October.

But Finch has an opportunity to prove he still has what it takes when Australia's tour of Sri Lanka gets underway in Colombo on Tuesday night.

After experimenting with batting at number three during the home series against Sri Lanka in February, Finch will open with David Warner during the three T20s and five ODIs.

"It was really good to be able to get a good block of rehab and I suppose almost some time off the knee to be able to fully heal," Finch said.

"It feels as good as it has since the surgery.

"I'm really confident my movement and everything can be as sharp as it possibly can and where I need it to be successful at international cricket.

"That's been a real positive over the last couple of months."

Meanwhile, Australia are sticking with Steve Smith in the middle order as Josh Inglis is the unlucky batter to drop out for the series opener.

Inglis could not have started his international career any better after averaging 35.8 following his first six T20Is.

Finch is certain Inglis will not just be warming the bench during the tour of Sri Lanka and will have a chance to play in the white-ball games.

"The ability to free [Smith] up and play his natural game and play the game in front of him is so important," Finch said.

"He's someone who can read the game as well as anyone, so it's about giving him the freedom to take the game on.

"We've got all the confidence that he can play that role unbelievably well.

"[Inglis is] really stiff.

"Every chance he's had he's taken with both hands and he's a super talented young player.

"He's shown his ability to float throughout the order in international and domestic cricket.

"He'll definitely get an opportunity at some point with the quick back-ups of the three T20s and the five ODIs being very congested."

The opening T20 clash begins at 11:30pm tonight AEST, before the second clash on Wednesday night and a third on Saturday. The ODI series begins on June 14.

AAP