'To all the fans, I want to thank you all from the bottom of my heart for helping me to understand and feel the greatness of Arsenal.
"It has been a year and a half full of emotions, of great moments and some other more bitter ones", he said.
Former Swedish worldwide Ljungberg lined out for Arsenal for 9 years between 1998 and 2007, and returned to north London to take charge of the club's U23 side last summer.
"But not a single day has gone by without me stopping to think about how lucky I have been to work for this club with these players and their professional and personal qualities".
He tweeted a picture of himself taking training and wrote: "However long I oversee Arsenal for I will give everything I have to put smiles on faces again". The Gunners have not won a Premier League match since October 6 against Bournemouth.
Arsenal had a distinctive, easy-on-the-eye approach under Wenger but Emery's team had no discernible style, even though he stated his intention to adopt a high-energy pressing game upon his arrival.
The north London side head into the game after a miserable run of form in the top flight has left them well off the pace in the race for Champions League qualification. "He (Emery) seems to have lost the players and the desire has ebbed away".
Arsenal fans had demanded "decisive action" from directors with the club's present run of five draws and two defeats this season just one match off equalling George Graham's run of eight without a win in 1992.
Emery's cause has not been helped by the stripping of the captaincy from fiery Swiss worldwide Granit Xhaka after he swore at Gunners fans when being substituted against Crystal Palace last month.
The Arsenal manager is likely to go with the pairing of Lucas Torreira and Matteo Guendouzi in central midfield while Mesut Ozil plays in a more advanced role. Emery is the third Premier League manager to depart this season after Pochettino and Watford's Javi Gracia. "The more hard challenge is to recruit a suitable successor".
"The search for a new head coach is underway and we will make a further announcement when that process is complete".
"The AST has always been advocating that the most important changes needed at Arsenal are in the boardroom, where Arsenal need better governance".