Lacazette, 31, was stung several times in the forest around Lyon's hotel in Sint-Michielsgestel in the Netherlands, where they are on a preseason camp.
The news was initially reported by L'Equipe, and a source has now confirmed to ESPN that the striker is being monitored on a day-to-day basis to see if he can take part when Lyon face Feyenoord this weekend.
Lyon also have a friendly against Willem II scheduled for Saturday.
Lacazette returned to Lyon this summer on a free transfer after leaving Arsenal. He spent five years at the Emirates after joining from the French club in 2017 and scored 71 goals in 206 appearances for them.
The 31-year-old began his career at Lyon, where he scored 129 goals in 275 games from 2010-2017.