Dean Henderson became a cult hero in south London after saving a penalty in Crystal Palace’s victory against Manchester City in last season’s FA Cup final. The England goalkeeper then boosted his popularity when he dropped into a local pub as supporters celebrated August’s penalty shootout victory over Liverpool in the Community Shield and put £1,000 behind the bar.

Henderson, made captain when Marc Guéhi was sold to Manchester City in January after Palace were humbled in the Cup by non-league Macclesfield, must be wondering how things have turned sour at Selhurst Park so quickly. Supporters turned on the manager, Oliver Glasner, during the first leg of the Conference League playoff against Zrinjski Mostar in Bosnia and Herzegovina last week and demanded his sacking after another unconvincing performance in the 1-1 draw.

A banner unveiled in the Holmesdale End at the start of Sunday’s 1-0 win against Wolves – only Palace’s second victory in 16 games – took aim at the board and lamented “missed opportunities” since a first major trophy was secured at Wembley last May. It also described Glasner as “finished” after he had told fans to “stay humble”.

Glasner was on his best behaviour as he looked ahead to Thursday’s second leg against Zrinjski, having struck another uneasy truce with the Palace chair, Steve Parish, to see out his contract until the end of the season, meaning it was left to Henderson to issue the rallying call.

“Unity: I think it’s important that we have that,” Henderson said. “It’s been a difficult period and I think the players have to take a lot of responsibility, because we’ve got to do better, first and foremost. For whatever reason it was, we had too many injuries and we just couldn’t cope with the amount of games and the quality we were up against in the Premier League over the last couple of months.

“Now we’ve got everyone back and we’ve got a squad, we’ve been picking up some good results, so hopefully that can give the club a boost. We’re playing European football … and it should be a time for everyone to come together and enjoy that.”

Henderson added: “It’s time to shift the narrative and really smile and enjoy these moments because they don’t come round often, instead of putting all the negative spin on everything.”

One of Glasner’s gripes after the first leg was that some of his players have had their eyes on their next move – an accusation many Palace fans will feel applies to him too. Jean-Philippe Mateta, who Glasner expects back soon from the knee injury that scuppered his January move to Milan, Adam Wharton, Daniel Muñoz and the out-of-contract Daichi Kamada are among those linked with summer moves. Henderson, who is expected to be Jordan Pickford’s backup at the World Cup, warned anyone not committed to the cause they were in for a rude awakening.

“If you don’t put the performances in order, you don’t get the move you want, so they need to be very careful,” he said. “I’m not aware of any of that, but I would suggest they have to be careful if they were thinking like that.”

Wharton’s form in particular has dipped in recent weeks but Glasner pointed out that the England midfielder had already played more than 1,000 minutes more than he had last season, owing to Palace’s involvement in the Conference League.

“Players have to cope with a completely new situation in their career,” he said. “I remember I spoke to Eddie Howe at Newcastle when they played the first time in the Champions League. They were massively struggling and I spoke about his experience. But we are still the second-best amount of points ever [at this stage for Palace].

“We have the European competitions and we have had some big injury problems at the end of last year. We had the Afcon [Africa Cup of Nations], we had some big noise in any single transfer window, and when I see the big picture, everything that happened for me, it’s just incredible where we are right now.”

Palace are three points behind eighth-placed Bournemouth in the Premier League and Glasner insists whoever replaces him could be competing in Europe again next season. He won the Europa League in 2022 with Eintracht Frankfurt before falling out with the hierarchy the following season despite reaching the German Cup final and is aiming to reach a fourth final in five seasons. But, perhaps wisely given Palace’s difficulty in breaking down low blocks, he was wary of making the bold prediction that Palace can go all the way before Zrinjski’s visit.

“I think for 120 years Crystal Palace entered every cup competition to win it,” he said. “This group of players has done it once last year. Every team will enter the competition, but just one can leave with the trophy at the end, and it just makes no sense to talk now about it.”