The Chilean has been out injured since the end of November after picking up an injury in the 1-1 draw with Norwich City and then aggravating it in training before Christmas.
He is now close to being back at full fitness though, and could play some part in their third round FA Cup clash with Sunderland at the weekend.
That could be a huge boost to the side, with a run out against the Black Cats potentially helping his fitness and making him available for selection against Liverpool a week on Wednesday.
In further news, fellow Arsenal midfielders Mikel Arteta and Tomas Rosicky have returned to training after their prospective injuries, reports the Telegraph.
Arteta has not played since picking up a calf injury in the loss to West Brom, while Rosicky has been missing since August after undergoing knee cartilage surgery.
Saturday’s game is likely to be too soon for them, but they could provide a boost to Arsene Wenger further down the line, with him having had to contend with a number of injuries hitting his squad this season.