Alexandre Lacazette has an extra year remaining on his current deal compared to Aubameyang.
The former Borussia Dortmund forward's contract expires in 2021, and he will have turned 32 by that time.
France international striker Lacazette, meanwhile, is tied down until 2022 and is younger than Aubameyang.
No.9 Lacazette will have only just turned 31 come the end of his deal. As a result, there is greater precedent to discuss terms with Aubameyang first.