LONDON — Manchester United boss Ruben Amorim said his team is still improving, as Sunday's dramatic 5-3 FA Cup penalty shootout victory over Arsenal points to a more positive future after a difficult start to life at Old Trafford.

United fans have suffered several false dawns in recent seasons, with development under Amorim's predecessors Erik ten Hag and Ole Gunnar Solskjaer largely a case of one step forward and two steps back.

Amorim may have wondered if he had taken on a poisoned chalice when a three-game unbeaten run to begin his reign was followed by a woeful run of results, with an unlikely victory over Manchester City in the middle.

But having outperformed expectations with a brilliant display against Liverpool the previous weekend, United followed that up at Arsenal to keep its FA Cup defense alive.

Amorim said he was particularly pleased with United's improvement on its 2-0 league defeat by Arsenal last month, when both the Gunners' goals came from set pieces.

"We deserved to pass through this round because we suffered all together and showed character," said United boss.

"I think we played, especially in the first half, we played better than in the first game," Amorim said.

"We were better in set pieces today, more aggressive. We showed a different spirit, even with 10 men, we are improving on that aspect."

Second-choice goalkeeper Altay Bayindir and forward Joshua Zirkzee were ultimately United's heroes on Sunday after recent criticism.

Zirkzee was booed off as a first-half substitute in last month's defeat to Newcastle United, while Bayindir was blamed for United's League Cup exit against Tottenham Hotspur.

But both were key contributors to United's third-round win, where it was reduced to 10 men, which Amorim said was a lesson for his squad.

"Your life as a footballer has cycles and moments and sometimes in one week your life can change," he said.

"You can see Altay — against Tottenham everybody was pointing the finger (at) Altay and I understand that and today he was our hero also.

"Joshua a few weeks ago had a small problem with our fans and today every time he's going on the pitch you feel the support from the fans.

"Then he has the last penalty, so life is like that and you have to continue (being) humble, to work every day, your time will come."

Amorim also said he was not sure if forward Marcus Rashford, who was again left out of the squad, had played his last game for United.

"He's a player for Manchester United, we'll see, he has to work, he has to represent his club and he loves his club, but I have to make choices," he said.

'Incredible' Arsenal

Arsenal boss Mikel Arteta said he was astounded his side could not finish off 10-man United on Sunday.

The host came from behind to level, Gabriel Magalhaes cancelling out Bruno Fernandes' opener after United's Diogo Dalot was sent off, and could have taken the lead through a controversial penalty.

But captain Martin Odegaard's spot kick was saved by Bayindir, who produced the only save of the shootout from Kai Havertz to send United through to the fourth round.

Arsenal had multiple chances to score a winner at 1-1, with Havertz guilty of missing a relatively simple chance inside the last 10 minutes of normal time, and Arteta could not quite believe his team was on the wrong side of the result.

"Incredible how you don't win the game," he told reporters. "The dominance, the superiority in relation to the opposition and everything that we did to try to win the game and that's it.

"We didn't get what we deserved clearly, but there is an element that is about putting the ball in the back of the net.

"We did it once and with the amount of situations, chances, penalties that we had we didn't (again).We go home extremely sad but I cannot be prouder of my players."

Arsenal came into Sunday's match unbeaten in 10 Premier League games and having trimmed Liverpool's lead to six points, albeit having played a game more.

But Sunday's FA Cup exit, following a 2-0 home defeat by Newcastle United in the first leg of their League Cup semifinal, narrows the Gunners' prospects of silverware this season.

Arsenal next welcomes local rival Tottenham Hotspur to the Emirates Stadium on Wednesday, but Arteta played down any additional pressure after two straight cup losses and insisted he was focused on the quality of its performances.

Jesus 'big worry'

Gabriel Jesus was carried off the field on a stretcher in visible discomfort in the first half on Sunday and Arteta said he feared the Brazil forward could face a prolonged spell on the sidelines.

"Big worry, that's my feeling," Arteta said. "He had to come off on a stretcher with a lot of pain, touching his knee and he's not looking good."

The Brazilian was hurt while attempting to tackle Fernandes from behind as the United captain prepared to take a shot.

Jesus immediately signaled to the bench that he was in pain and had his jersey over his head as he was taken off the field in the 40th minute, to be replaced by Raheem Sterling.

The precise nature of Jesus' injury wasn't immediately clear. Arteta was asked if it was an injury to the right knee on which Jesus required surgery in December 2022, and said: "No, I think it's the other one.

"The worrying factor is the feeling he had when he had to come off and the pain that he was in."

Arsenal played with an extra man from the 61st minute after United defender Dalot's red card, but could only score one goal — a deflected shot from defender Gabriel.

Arsenal is shorn of firepower with Bukayo Saka out during last Tuesday's loss to Newcastle in the League Cup semifinals with a hamstring injury and Jesus now set to be sidelined.

Arteta could face more calls to sign a forward in the transfer window this month.

"We miss from various ways, from different players," Arteta said. "I understand, guys, but I cannot love our players more and I am very much focused on the ones I have to perform at the highest level."

Reuters