Three months after playing in the semi-final of one competition and coming agonisingly close to securing a place in this season's Champions League, West Ham are about to start the campaign in another.
And this time it's against opponents who two years ago were part of a league where a third of clubs had a ground capacity of 4,000.
The frustrations felt at defeat over two legs to Eintracht Frankfurt in May was only compounded as the German side went on to beat Rangers in the final.
So, instead of taking their place in Europe's number one club competition for the first time, the Hammers find themselves in the Europa Conference League.
West Ham's initial assignment is a play-off with little-known Danish outfit Viborg, who were only promoted two years ago. Should they get through, they could meet opponents as varied as last season's Champions League semi-finalists Villarreal or FC Vaduz from Liechtenstein.
Skipper Declan Rice will miss both play-off matches after picking up a two-match ban for his angry reaction to the second-leg defeat in Frankfurt, while full-back Aaron Cresswell sits out the opening match after his red card in Germany.
It puts the onus on other players to get West Ham past Viborg, which would trigger a €2.94m (£2.47m) payment from Uefa for reaching the group stage.
Continued participation is also seen as preferable when it comes to making a compelling case for Rice to stay at the club.
Despite repeated links with Chelsea and Manchester United, the Hammers have made the firm decision to keep Rice, who still has two years left on his contract, and the option of an additional season.
The 23-year-old, who is expected to be a key figure in Gareth Southgate's England World Cup squad later this year, has turned down a number of attempts by the London club to extend his present deal and the general expectation is he will leave the next summer.
However, the Hammers have not given up yet on keeping him and accept they must offer the highest possible platform for Rice to display his talents, even if, in his most recent observations around his future, the midfielder claimed not to be concerned by it.
"There is no point talking about anything," he told Sky Sports last month. "I can't control what happens off the pitch. I am a West Ham player. I have a West Ham contract and I will always respect that.
"All I can do is going on the pitch, play football and be happy. For the last couple of seasons that is what I have done."
After losing their opening two Premier League games, West Ham are second bottom of the table.
Newcomers Maxwel Cornet and Gianluca Scamacca are still getting used to their new surroundings, while deals for Brazilian defender Emerson Palmieri and Paris St-Germain's Thilo Kehrer in the process of being completed.
Manager David Moyes openly admitted his side are "a bit behind" and "might take time to get up and running", so the Scot could be forgiven for not wanting a pair of midweek assignments that disrupt preparations for key domestic matches against Brighton and Aston Villa.
Moyes is having none of it.
"[The tournament] is an absolutely fantastic thing," said Moyes, who won't be in the dugout after being sent off in last season's exit.
"We finished seventh in the league last year and the fact people are talking about Europe is good.
"There are so many teams in the league who would shake your hand and thank you for European football.
"It is a great thing for West Ham. We have a play-off and we want to get through."
Some West Ham fans will never accept the London Stadium as their home or the rationale that lay behind the move out of Upton Park in 2016.
However, years of complaints about the sterile atmosphere inside the former Olympic Stadium was silenced during last season's European run. The noise that erupted around West Ham's thrilling last-16 victory against Sevilla will not be forgotten in a hurry.
Club officials believe the campaign brought the club closer together after years of in-fighting. Uefa praised West Ham for its pre-match 'show', which in English terms was innovative in its use of a live in-house DJ.
West Ham only put their 1,100 ticket allocation for the second leg on sale on 15 August, but expect it to be sold out well in advance of next week's trip to Denmark.
Given the club's recent European history, supporters will be taking nothing for granted.
Prior to last season, the Hammers' last three European campaigns yielded just four victories from 12 games, two of which came against a team of part-timers from Andorra.
But, make no mistake, Moyes wants to win. The Europa Conference League may not have the greatest reputation but, for West Ham this season, it will do just fine.