The last time Crystal Palace played in the FA Cup, they were celebrating the best moment in their history. On Saturday, they experienced what must be the most embarrassing day in their 120-year existence.

Defeat by non-League Macclesfield in the third round was the ultimate humiliation. Palace were not just beaten by plucky underdogs who sat back and defended for their lives but outplayed by a team 117 places below them in the football pyramid.

Acceptance came at full time from captain Marc Guehi in front of the travelling supporters on the terrace, the centre-back telling them “We know, we know”, acknowledging it was unacceptable. Goalkeeper Dean Henderson and assistant manager Paddy McCarthy joined him.

There was a special match ball, and a badge on the Palace shirt sleeves, as if anyone needed a reminder of last year’s success. An exhibition was held this weekend in the Crystal Palace subway to celebrate it. “This gives us a responsibility to show our standards,” manager Oliver Glasner said in his pre-match press conference. “It doesn’t mean we have to win it again, but it’s to show our standards. I don’t feel pressure, but responsibility.”

Before the game, Glasner spoke about the importance of “not taking the second step before the first one” but his team did not heed those words in an awful performance. They were rattled mostly by the striking physicality and determination of their National League North opponents.

“We have to show ourselves, who we are, our talent, who Crystal Palace is, our standard,” Glasner added before the game. “I don’t care what the opposition is doing; this was the same before the final. There’s a big gap between Macclesfield and (Manchester) City but the approach must be the same.“

The artificial pitch was another reason why centre-backs Guehi and Chris Richards found it difficult to judge the bounce of the ball, but with their ability, that must not be an excuse. Adaptation is crucial. They have played twice before this season on such pitches. D’Mani Mellor, the Macclesfield No 9, induced panic throughout.

The home team’s captain, Paul Dawson — with his bloodied, bandaged head from a challenge with Jaydee Canvot in the first minute — summed up the contrasting levels of desire, heading home unmarked from a free kick two minutes before half-time.

In his post-match press conference, Glasner reeled off a list of things his side failed to show — “no physicality, nobody who could dribble past one from a physical presence, not being in the dangerous areas, no kind of quality today in attack” — before repeating himself, perhaps in disbelief.

“I saw our players lying on the ground and complaining about getting a foul,” he said. “I played for 19 years in these kinds of games. You don’t need a tactic or a manager who tells you what to do; I expect that you do the right things.”

Oliver Glasner has gone from FA Cup winner to victim of its greatest shock (Darren Staples/AFP via Getty Images)

He told TNT Sports he could have put out the under-21 side and they would have performed better.

Yet, perhaps seeking to take some of the heat off his players, he said the defeat was his responsibility. Glasner insists he must find solutions to the problems his team face.

He will potentially change his system, as he did at half-time on Saturday, to play four defenders and an extra attacker, and he confirmed he will look at his team’s structure, which he described as “wild” against Macclesfield.

If the answer is simply that they have Daniel Munoz, Ismaila Sarr and Daichi Kamada back, and that new signings are needed, then it is time to say that, rather than dancing around the issue.

But it is clear that some players are either not up to the level required, struggling to adapt as quickly as Palace need or run into the ground by the lack of rest and congested schedule. Borna Sosa has struggled and Yeremy Pino is still frustratingly inconsistent.

Christantus Uche, when given his chance, has failed to take it. He fell to the floor too easily, too often against Macclesfield and had Palace’s best chances, only to waste them. Glasner does not trust him, which has not helped, but the manager must take personal accountability for his struggles, too.

These players’ shortcomings remain a failing from the summer transfer window, as does Glasner’s stubbornness with team selection in previous games. It should not have ended in defeat to a non-League side.

A block of four weeks during which they will finally be able to train properly due to no midweek game should help to fix things, but lingering on this defeat is a one-way ticket to further embarrassment in the Premier League.

For all the apologies that will come, words are a waste of time. There have been so many of those in the past weeks of disappointing results, and the repetition about finding solutions will start to grate. The problems have been apparent for the past few months and the post-mortem will go on externally, but it is important Palace shut out the noise and shift their focus quickly back to the Premier League.

Their players will report back for training on Tuesday, with Glasner requiring them back a day earlier than they were originally due, allowing Sunday for recovery and Monday remaining a day off.

This was the “match of the decade”, the “David and Goliath story”, as Glasner said before the game, and they will have to “accept it”. Words must translate into actions.

Palace had their day at Wembley in May, now Macclesfield deserve theirs. Palace must move on quickly.