Sri Lanka's Pathum Nissanka was ruled out of the second Test against Australia ahead of Monday's fourth day in Galle after testing positive for Covid-19.

Opening batsman Nissanka is the sixth player from the Sri Lanka squad to test positive during the past two weeks.

"He was found to be positive during an Antigen test conducted on the player yesterday morning, following the player complaining of feeling unwell," a Sri Lanka Cricket statement said.

"Nissanka was immediately isolated in a different hotel upon identification and will undergo Covid-19 protocols."

Oshada Fernando will replace Nissanka in the team when play begins on Monday with Sri Lanka resuming their first innings on 431-6, a lead of 67.

Sri Lanka suffered a Covid outbreak on the eve of the final Test.

Angelo Mathews returned to the team for the second Test after testing positive during the opening match, which the hosts lost.

Praveen Jayawickrama, Dhananjaya de Silva, Jeffrey Vandersay and Asitha Fernando have also tested positive.