Both players have become ill and will not go with the team to the away match against Brentford, reports The Athletic.
A heavy message for Arsenal, who already have Thomas Partey, Eddie Nketiah and Gabriel Magalhaes on the injury list.
Aubameyang scored 15 goals in 39 games last season and Lacazette accounted for 13 goals in 31 games when Arsenal finished in eighth place in the league.
In the newcomer Brentford, the Swedes play Pontus Jansson and Saman Ghoddos.