He was a surprise inclusion in the Arsenal XI, which also featured Jack Wilshere, Mathieu Debuchy, Mathieu Flamini and Mikel Arteta, who are all coming back from various injuries.
Arsenal won the game 4-0 with two goals from Alex Iwobi, one from Wilshere and another from Dan Crowley.
Diaby started the game and played 45 minutes, and made an impact before his substitution, which was scheduled prior to kick off.
The Frenchman set up Alex Iwobi's first goal with an incisive pass, and his lay-off to Mathieu Flamini to shoot led to Jack Wilshere scoring the rebound.
Diaby has not played a single Premier League game this season due to a struggle to get fit, making his only appearance in the League Cup in a defeat to Southampton.
He is out of contract at the end of the season and has done little to justify being handed a new contract so far, but an injury free end to the season could yet sway manager Arsene Wenger into renewing his deal.
Here is a look at how fans reacted on Twitter to his comeback...
Is anyone else thinks it's weird how diaby is back just in time for the Liverpool game when he had one of his best if few games for us #afc— stuart p-t (@stusaxon71) March 31, 2015
Diaby staying fit now until the end of the season. Plays a few games. Looks amazing. Gets a new 4yr contract. Legs fall off pre-season. #AFC— i.am.quotes™ (@AsTallAsHerEyes) March 31, 2015
Good to see Wilshere back and scoring. Diaby actually started? Wow... #afc— Kanö (@Kane2602) March 31, 2015
If Diaby stays fit until the end of the season, Wenger will do the same as he did with Vermaelen. Can't see him at Arsenal in the future.— Baptiste Paulista (@KnockoutArsenal) March 31, 2015
I would love diaby Couqelin at Cm on Saturday. Come on wenger do it— Franko (@santi_franko) March 31, 2015
Wenger said in March that if Diaby was fit he would consider giving him a new deal. Guess what, yes, Diaby is back in training.— Alexis is a Gooner (@afcmark1) March 31, 2015
Diaby just so happens to return to full training before end of the season again kmt... Watch Wenger extend his contract like a wasteman