Gunners scouts were present at Stade Geoffrey-Guichard during the Ligue 1 club's 2-2 draw with Rennes on Friday night, running the rule over the two prospective summer transfer targets.
Arsene Wenger sent Gilles Grimandi to make a personal check on striker Aubameyang and goalkeeper Ruffier, as he considers bringing the pair to the Emirates Stadium ahead of next season.
Grimandi was said to be so impressed that he has ordered Arsenal's chief scout, Steve Rowley, to fly out to France and watch them himself.
Ruffier has been in scintillating form this campaign, and has been instrumental in Saint Etienne's impressive defensive record, that has only been bettered by Ligue 1 leaders Paris Saint-Germain.
The France international could be brought in to provide competition for current number one, Wojciech Szczesny, who has endured a difficult season in north London.
Aubameyang, meanwhile has caught the eye with a string of impressive performances, that has led Les Verts to slap a £12million valuation over the head of the former AC Milan star.
The Gabon centre-forward was believed to be the subject of a bid from Newcastle United during the January transfer window, and speculation has continued to mount that he'll head for the Premier League this summer.