Dinesh Chandimal has confirmed Lahiru Kumara will miss the second Test with Australia and Sri Lanka's subsequent tour of South Africa due to the injury he suffered in Brisbane.

Seamer Kumara sustained a hamstring injury on day two at the Gabba and did not bat as his side were skittled for 139 on day three to lose by an innings and 40 runs.

After the second Test in Canberra that starts on Friday, Sri Lanka begin a two-Test series with South Africa on February 13.

Speaking at a news conference, skipper Chandimal said of Kumara: "According to a physio assessment, he's out for four to six weeks, so he definitely will be out for the South Africa tour."

Sri Lanka failed to pass 150 in either of their innings in Brisbane as Pat Cummins returned match figures of 10-62.

"We are really disappointed as a team," said Chandimal. "Our batting was below par throughout the game, so that's the one area we'll have to improve.

"If you can't score 300 in an innings, it's always tough to beat a team like Australia, especially playing in Australia.

"Credit goes to the Australian bowlers as well. They were outstanding, especially Pat Cummins. When you play at the Gabba, you always get extra bounce. The main thing is he hit the right areas and right lengths. He's a brilliant bowler."

Chandimal made five and nought batting at number three but has no plans to drop down the order.

"I just want to keep batting at number three," he insisted. "The last years I batted at number five because some times I had to take the keeping gloves, but now [Niroshan] Dickwella is in good shape and so as an experienced player I have to come up in the order and play the role the team wants."