Warner faces a fight against time to overcome the broken left index finger he hurt in the one-day tri-series in the West Indies last month, and has only began batting properly in the nets in recent days.

He also skipped last week's inter-squad mid-wicket trial match, where back-up opener Shaun Marsh struck an unbeaten century against the likes of Mitch Starc and Josh Hazlewood.

Warner was originally expected to miss between two and six weeks with the fractured index finger. He resumed batting with one hand in the nets against the slow bowlers last week.

However, Australian team officials say he is still on track to play in the first Test, which begins in Kandy on July 26.

The tourists began a three-day clash against a Sri Lankan Board XI in Colombo on Monday.

Skipper Steve Smith opted to bowl first, and the tourists capitalised by leaving the Board XI at 3-41 after the opening hour. Mitch Starc, Jackson Bird and Mitch Marsh had each claimed a wicket.

Heading into the clash, allrounder Marsh said he was ready to accept whatever role was required in the three-Test series.

"I think depending on the outlook of the team and whether they bowl two spinners or three quicks and me, my role will differ. But for me it's about just playing the conditions, I will be attacking the stumps as much as I can, with fields that allow me to bowl like that," he said.

"I think if we've got two spinners I'll probably bowl a bit more with the newer ball being the third seamer. It's always nice in these conditions to bowl when the ball's a little bit harder and potentially swinging a little bit, but I don't really mind, I'll just bowl wherever the skipper needs me to bowl. Whatever the selectors go with, I'll just prepare as best I can."

Marsh said the Australian batsmen knew they had to be assertive early in their innings.

"That's something we've spoken about as a batting group already, just being as sharp as we can to start our innings. I think conditions, whether it is spinning or whether it is reverse swing, it's always going to come into it massively when we're batting," he said.

"I'll be preparing as best I can over the coming week for the different conditions, and I think the start of the innings here is really important."

Spinners Stephen O'Keefe and Nathan Lyon faced an important hit out in the tour match, as selectors debated whether to play both men.

Paceman Josh Hazlewood had been overlooked. Gloveman Peter Neville, having had an upset stomach last week, was selected.

Australia squad: Shaun Marsh, Joe Burns, Usman Khawaja, Steve Smith (c), Adam Voges, Mitch Marsh, Peter Nevill (wk), Mitchell Starc, Stephen O'Keefe, Nathan Lyon, Jackson Bird, Nathan Coulter-Nile (12th man to be named).

-with AAP