There is still no clear successor identified at Arsenal ahead of the imminent departure of Arsene Wenger. Photo: Scott Heppell/Reuters

LONDON – It is clear that Arsene Wenger will be an extremely reluctant guest at the farewell party Arsenal are throwing for him on Sunday at the stadium he pretty much built.

Notwithstanding his bitter disappointment at losing the Europa League semi-final on Thursday, meaning he will have no grand finale nor another Champions League qualification to add to his CV, his demeanour since his departure was announced last month has betrayed his frustration with the decision.

The tension between Wenger and the executives sizing up his replacement has been significant, and those close to the club confirm that the distance between them is considerable.

The debate among those executives over his successor has not yet settled on a clear candidate. But there is increased discussion over taking the bolder path of appointing a younger figure.

Patrick Vieira, Mikel Arteta, and even Thierry Henry are the names featuring in that discussion, with 30-year-old Hoffenheim coach Julian Nagelsmann the favoured candidate among those without an Arsenal connection.

That would also have the effect of placing more power in the hands of chief executive Ivan Gazidis, director of football relations Raul Sanllehi and head of scouting Sven Mislintat.

Could one of Thierry Henry or Patrick Vieira take over as Arsenal manager from Arsene Wenger? Photo: Reuters

It would also allow Josh Kroenke, son of Stan, to assume greater influence, with the 37-year-old seen by some at the Emirates as the future chairman of the club.

The leading candidate of the established and older coaches is Juventus’ Max Allegri, given that the logistics of appointing Joachim Low during a World Cup campaign seem too complex.

Luis Enrique looks to have priced himself out of the job, as he has at Chelsea, with expectations of a wage in excess of the £9 million a year currently paid to Wenger.

All of the youthful options would be a risk, and Henry would need to be partnered with a more experienced coach, given that he has been limited to roles with the youth team at Arsenal and working as an assistant to Roberto Martinez with Belgium.

Whoever does succeed Wenger will inherit significant issues with the club and the team. There are still two games to play, and Burnley would go on to equal points with Arsenal if they beat them today.

So it is conceivable Arsenal could yet finish seventh – the last of the Europa League slots available to Premier League clubs.

That would mean Wenger’s successor would start his tenure on July 26, not on a lucrative summer tour in Singapore on the day when they are due to play Atletico Madrid, their Europa League vanquishers.

Instead, they will be heading to a far-flung corner of Europe to play in the second qualifying round.

If the tour has to be cancelled, it could cost up to £5m. That is on top of the estimated £9m they are losing in sponsorship revenue from Puma and Emirates, who pay 15 percent less when they miss out on the Champions League.

Of course, it is also another year of missing out on Champions League TV revenues, though with their run to the semi-final, Arsenal might accrue almost £40m from the Europa League this season, given that they were the only English club to progress beyond the group.

But it will still be at least £16m down on what they earned from the Champions League in 2016-17.

The financial cost will only be part of the pain. The humiliation of dragging their way around Europe before the Premier League season starts to qualify for a tournament which is second best anyway ought to concentrate the minds of the players today.

Yet it is not simply a second successive year of not playing in the Champions League. The delay in appointing swiftly after announcing Wenger’s departure will complicate a narrow transfer window, which officially starts on June 9, when most players will be in World Cup camps and which, for Premier League clubs, ends on August 9.

The new manager is going to discover that much of his transfer kitty was spent in January. Arsenal gambled that the swap deal for Henrikh Mkhitaryan, the record £57.5m fee for Pierre-Emerick Aubameyang and the £350 000-a-week new deal for Mesut Ozil would be enough to fire them into the top four and the Champions League.

As it was, the Europa League proved their best hope to return to the elite, but Aubameyang was ineligible, while Mkhitaryan did not start in Madrid.

Ultimately they might have been better off sticking with Olivier Giroud, who was at least eligible to play.

Olivier Giroud was allowed to join Chelsea despite Pierre-Emerick Aubameyang being ineligible in the Europa League. Photo: Alastair Grant/AP

Recruitment will naturally be trickier anyway, given that Arsenal do not look like being back in the Champions League soon. Yet recruitment will also need to be extensive.

Petr Cech and David Ospina’s deals run out in 2019, so a new goalkeeper will be required. Bayer Leverkusen’s Bernd Leno, Germany’s No 3, is understood to be the favourite choice of Mislintat.

Arsenal need to reboot their defence once again and are in the market for a centre-half. Mislintat has already made a mark in that department with the signing of Konstantinos Mavrapanos in January.

It was encouraging for Arsenal that Mavrapanos made a favourable impression last week against Manchester United, but much of the £50m net spend available will presumably be spent on a new player in this position.

Jack Wilshere is on the verge of leaving and will need to be replaced. Aaron Ramsey, with one year left on his deal, will need to be sold this summer, as Arsenal do not believe he intends to sign a new contract.

Hector Bellerin is likely to push once again to move, with Juventus keen.

It is undeniable that Wenger has built a modern super club at Arsenal. It is beyond question that his greatest achievement is actually the stadium in which they celebrate him today.

Maintaining Champions League football while they repaid interest on the £390m debt was a monumental achievement.

But it is also true that, had he left four years ago after the 2014 FA Cup final, his legacy would have been unquestioned. By hanging on, he has bequeathed his successor an in-tray of problems.