The 26-year-old France international started a game for the first time in three months after suffering with a thigh injury picked up during the Gunners’ clash with Chelsea in September.
Diaby took to the pitch in place of the injured Mikel Arteta who was ruled out with a calf strain and Wenger believes the Frenchman will get better with each game he plays.
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"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."
Diaby was replaced just after the hour mark by Aaron Ramsey, and said he was delighted to make his comeback.
"It helped me because when you come back you need games and a bit of rhythm to be fully back," Diaby added. "It was very good, and I am pleased I played in that game.
"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 [to the injury]. 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."