CA confirmed media reports that Cummins was dining at an Adelaide restaurant on Wednesday night where a positive COVID-19 case was identified.
Australia skipper Pat Cummins has been ruled out of the second Ashes Test in Adelaide after being identified as a close contact of a COVID-19 case, elevating Steve Smith to the captaincy for the first time since 'Sandpaper-gate' in 2018.
The board said fast bowler Cummins would need to isolate for seven days, meaning he would miss the day-night second Test starting later on Thursday, and would look to play in the third match in Melbourne from Dec. 26.
CA confirmed media reports that Cummins was dining at an Adelaide restaurant on Wednesday night where a positive COVID-19 case was identified.
Fast bowler Mitchell Starc and spinner Nathan Lyon were dining at the same restaurant but at a separate table outdoors. They were deemed casual contacts and are free to play.
"(Cummins) did not breach any biosecurity protocols," CA said in a statement.
"He isolated as soon as he became aware of the situation and has since had a PCR Test, which produced a negative result.
"SA Health has confirmed that Cummins is a close contact and will be required to isolate for seven days."
Vice-captain Smith regains the captaincy nearly four years after losing it for his involvement in the 2018 Newlands ball-tampering scandal.
Smith was suspended from international and most domestic cricket for 12 months and also banned from leadership roles in the Australian set-up for two years. The leadership ban expired in March 2020.
Cummins, the world's top-ranked Test bowler, led Australia to a nine-wicket win over England in the Ashes opener in Brisbane, his first match as captain.
His absence from the day-night Adelaide Test, which starts at 2:30 p.m. local time (0400 GMT), is a blow for Australia as they look to take a 2-0 lead in the five-Test series.
The home side have now lost two of their first-choice quicks, with Josh Hazlewood having been replaced in the attack by Jhye Richardson after suffering a side strain at the Gabba.
Uncapped pace veteran Michael Neser replaces Cummins in the attack for his Test debut in the pink ball match.
"Cummins is understandably very disappointed not to be able to captain Australia for the day-night Test in Adelaide," CA said.
Middle order batsman Travis Head will be vice-captain.
CA declined to comment as to whether they would review their biosecurity arrangements for the remainder of the Ashes.
The only limits on players with regards to mixing in public are that they head out in small groups.
