Arsenal paid £11million to get Arsene Wenger quit at the end of the 2017-18 season.
The club on Friday morning confirmed Wenger would end his 21-year reign at the end of the current season.
The Gunners have struggled in the Premier League this campaign and face a second season of finishing outside of the top four.
A route back into the Champions League and a final chance of silverware for Wenger come in the shape of the Europa League – with Arsenal facing a two-legged semi-final against Atletico Madrid.
Although Wenger has been criticised by the fans and some former players in the last year, Arsenal chief executive Ivan Gazidis admits the Frenchman cannot be replaced as he leads the search for the next man to lead Arsenal.
“I have often said (replacing Wenger) is the biggest challenge we face,” he said.
“In the coming months, the world will see the unity and power of this football club, and the people within it.
“We are not going to find a replacement for Arsene Wenger – we have to find a new path forward.
“I don’t think the club has ever been better prepared for that decision. Now it is time to look forward and I think we can do that with confidence.” Ivan Gazidis added.
Managers like Celtic boss Brendan Rodgers, Massimiliano Allegri of Juventus and former Chelsea and Real Madrid coach Carlo Ancelotti have been tipped to replace the Frenchman at the Emirates.
Gazidis would not be drawn on any targets to replace Wenger but revealed the criteria he will be looking for from any potential candidates.
“It is important to me that we continue the football values that Arsene has instilled in the club, he added.
He further stated: “I want to see somebody who can continue that for our fans, and our fans want to see that.
“Somebody who will continue to play exciting, progressive football that gets people interested and excited in the games we play.”