Manchester City's players will regret the opportunities they have squandered in the Champions League in the past two seasons.
That is the belief of the head of one of their prominent supporters groups.
City surrendered a 5-3 first-leg advantage to crash out of Europe's elite competition on away goals with a 3-1 loss at Monaco on Wednesday.
The demoralising last-16 defeat was another tale of what might have been after last season's semi-final heartache against Real Madrid.
On both occasions City produced lacklustre performances in the decisive away legs but went out only by narrow margins.
Kevin Parker, general secretary of the Manchester City Supporters Club, said: "It was very disappointing. It is difficult for me to understand how a team cannot be up for it. Every single player in the first half under-performed. I still can't explain it almost 24 hours on.
"I wonder when I look at players, do they not realise the opportunity that has passed them by? In the first half yesterday it was reminiscent of the performance in the semi-final in Madrid last year.
"There almost seemed no belief in that semi-final. Even though they scored first, in reality all they needed to do was get a goal in Madrid, but there just seemed no belief.
"That probably surprises me more than anything, that a player would miss that opportunity. They may think they might get the opportunity again, but in reality I don't know how many of that group will get the opportunity again.
"I'm a bit down about it. I've had a season ticket for 44 years and it's probably not as bad as losing at Halifax, Lincoln and Wycombe, but it's all about expectation these days.
"We have a fantastic squad of players, a brilliant coach - but you wouldn't have thought that looking at that performance yesterday."
Monaco levelled the tie with two goals in the first half-hour as manager Pep Guardiola's plan to attack failed. City did not gain any meaningful possession in the first half as Monaco came at them and, although Leroy Sane put them back in charge in the 71st minute, Tiemoue Bakayoko won it soon after.
Questions have been asked of Guardiola's tactics and selection with the Spaniard coming in for some heavy criticism.
Parker said: "I think we have got the best coach in football and the team has under-performed, so I'm not surprised if the media give Pep and City a bit of stick. Some of it is justified, some not.
"To get knocked out in the last 16 of the Champions League and still not be in a position where we have qualified for next season will be disappointing internally at the club as much as it will be with the fans.
"But I'm not unhappy with Pep, I'm more than happy with him. I've seen enough to think we have a bright future with him but, from an expectation point of view, we probably expected more this season than we are going to get."