Sri Lanka skipper Kusal Mendis won the toss and elected to bat first against fellow winless Australia in the Cricket World Cup on Monday.

The island nation have made two changes at the Ekana Stadium in Lucknow after regular captain Dasun Shanaka was ruled out due to a thigh muscle injury in their defeat to Pakistan.

Fast bowler Matheesha Pathirana is also injured. Chamika Karunaratne and Lahiru Kumara make the team looking for their first win.

Five-time winners Australia have also lost their first two matches after they went down to India by six wickets and then suffered a 134-run thrashing against South Africa.

But they are unchanged in the hunt for an opening win in the round-robin tournament.

Skipper Pat Cummins said Australia would have also opted to bat had he won the toss, but added he doesn't "think it (bowling first) is too big a difference".

Australia have lost three of their last four ODIs to Sri Lanka.

AUSTRALIA: Mitchell Marsh, David Warner, Steven Smith, Marnus Labuschagne, Josh Inglis (wk), Glenn Maxwell, Marcus Stoinis, Mitchell Starc, Pat Cummins (capt), Adam Zampa, Josh Hazlewood

SRI LANKA: Pathum Nissanka, Kusal Perera, Kusal Mendis (wk, capt), Sadeera Samarawickrama, Charith Asalanka, Dhananjaya de Silva, Chamika Karunaratne, Dunith Wellalage, Maheesh Theekshana, Lahiru Kumara, Dilshan Madushanka