The French midfielder was an unexpected inclusion in the starting XI for Sunday's Premier League clash with Manchester City after Mikel Arteta suffered a calf strain in training prior to the game.
Diaby, who has struggled with injuries throughout his Emirates Stadium career, had been out of action since sustaining a thigh problem in the defeat by Chelsea at the end of September.
He lasted 61 minutes of Sunday's 2-0 defeat to the Premier League champions, with the Gunners reduced to 10 men after just 10 minutes when Laurent Koscielny was dismissed.
Diaby told the club's official website: "I feel good physically. Of course I have been out for a long time so I am not at my best, but importantly I did not get any reaction. This is good for the future.
"I knew the day before the game that I was starting, so I just had to prepare for that. I had been out for a long time, so I did not expect to be on the pitch so quickly.
"But it doesn't matter, you just need to be prepared and see how it goes."
Arsene Wenger admitted it was a 'gamble' to include Diaby against Roberto Mancini's men, but was happy with how the former Auxerre man coped with his comeback.
"Diaby became stronger during the game," Wenger said. "I feel he was like the team. He started very slowly and became stronger in the second part of the game. I took the gamble because I feel that it was needed. It's good that he came through well. He will become stronger very quickly.
"The team is desperate to do well and has quality. We need to be conscious that we have quality and we have to show more authority from the start in big games. The authority comes with the confidence in your quality."