Mathieu Debuchy suffered a cruel injury blow on Sunday as he limped out of the game against Bournemouth after just 15 minutes.
The 31-year-old had not started for the Gunners in a year, spending the second-half of last season on loan at Bordeuax, but saw his Arsenal comeback cut short when he went down with a hamstring problem.
Arsenal had just taken the lead through Alexis Sanchez, before the France international was forced off injured. Arsene Wenger brought on Gabriel in place of Debuchy at right-back, and will await news on the severity of his injury.
Debuchy last played for Arsenal in November 2015, coming off the bench in the Gunners' 3-0 Champions League win over Dinamo Zagreb. The loan in Ligue 1 as well as a calf injury saw him overlooked by Wenger since then, but he proved his fitness with the Under-23 squad to return to the starting line-up for Sunday's game with Bournemouth.
Arsenal's first-choice right-back, Hector Bellerin, is also currently sidelined, having been ruled out for six weeks with an ankle injury.
However, Bellerin could be in line for a return before Christmas, indicating that he is recovering well from the injury.
"It's going better than expected because it's a pretty hard injury but, at the moment, it's recovering really well," Bellerin told 101 Great Goals earlier this week .
"I hope to be running by the end of this week or the beginning of next week and then we'll just take it from there."