Diaby has struggled with injury since moving to the club in 2006, and the France international has admitted that he is keen to contribute to the team this season.
"I'm always confident because I know my ability and I know that as soon as I'm fit I can play at a good level. I always keep those references in my mind and I work every day to reach that level," he told the club's website.
"It was very frustrating because I did a lot of work to become fully fit last season and I wanted to play a full season. Unfortunately, two injuries kept me away from the pitch.
"I'm working back to my best level and beyond. I want to catch the train and bring something to the team. That's my objective."
Diaby has made 178 appearances for the Gunners, scoring 19 goals.