Aubameyang and Lacazette were conspicuous absentees for the Gunners’ poor 2-0 defeat to Brentford to open the new campaign on Friday.
The Gabon international has been linked with a move away from Emirates Stadium, with his unexpected absence fueling the speculation.
But Arsenal moved to clarify the situation, revealing Aubameyang was in contention to play in Sunday’s London derby against Chelsea.
“Auba tested positive for Covid-19 and was unavailable for last Friday’s match at Brentford,” the Arsenal update said.
“Auba is now negative on Covid-19 testing, is well and following all protocols for return to play. He will return to training and be assessed prior to Sundays match.”
On Lacazette, the update said: “Alex tested positive for Covid-19 and was unavailable for last Fridays match at Brentford. Alex is still recovering and will not be available for Sunday’s match.”
The pair along with Brazilian midfielder Willian and back-up goalkeeper Aron Runarsson have all tested positive.
Sunday’s meeting with Chelsea looms as a critical game for embattled boss Mikel Arteta, with the Blues potentially set to unleash new signing Romelu Lukaku.
The European champions won 3-0 over Crystal Palace in their opening league game.