The Gunners have been in contact with the Blues about taking the Senegal striker for the rest of the season. But they face competition from Roma for Ba, who has found himself out of favour under new manager Jose Mourinho.
The forward has not even made the bench for Chelsea's last two fixtures despite being fully fit, and slipped even further down the pecking order when the Blues signed Samuel Eto'o last week.
With Fernando Torres and Romelu Lukaku also at Stamford Bridge, Ba is unlikely to feature much this season.
Chelsea can trim their wage bill by loaning out the forward but might prefer him to go overseas rather than to a direct Premier League rival.
Arsenal had an interest in signing Ba permanently in January when he was at Newcastle United but were concerned about his history of knee trouble.
Arsene Wenger wants proven back-up for Olivier Giroud, who has begun the season in outstanding form.
The Arsenal manager has failed in a series of bids to land a new forward on a permanent deal this summer and has now adjusted his sights to a loan deal.
The Gunners are in advanced talks with Real Madrid to buy Ozil for €47 million and have agreed a loan deal with Palermo for Viviano, who arrived in London on Sunday night to put the finishing touches to his move.