Erik ten Hag vowed Manchester United would "give everything" to prevent Manchester City from matching his club's treasured treble after they beat Brighton to set up an FA Cup final against their fierce rivals.
United won 7-6 on penalties at Wembley on Sunday after the game finished goalless, with defender Victor Lindelof scoring the decisive spot-kick.
It went some way to banishing the agony of their shocking Europa League performance in midweek when they lost 3-0 to Sevilla in the quarterfinals to lose 5-2 on aggregate.
But they will have to find more of a cutting edge in the FA Cup final on 3 June if they are to beat Pep Guardiola's City, who are targeting the treble of Champions League, Premier League and FA Cup.
City are favourites to win all three of the trophies this season after moving up through the gears in recent weeks.
United were on course for three trophies of their own before Thursday's blowout in Spain, but they are still chasing a domestic double after winning the League Cup in February to end a six-year silverware drought.
United boss Ten Hag, speaking after the nail-biting Wembley shootout, praised his team's ability to bounce back.
"First we are physical, strong, we are mentally strong, so we showed the character and personality necessary... we were determined to win this game," he said.
But the Dutch boss said his men must learn to change the script during tough matches – they have suffered a number of punishing defeats this season, including a 6-3 defeat at City and a 7-0 reverse at Liverpool.
"What we have proved is that we can deal with setbacks, we can bounce back between games," he said.
"But now what we have to improve is to bounce back in a game in difficult situations or occasions, away stadiums – it doesn't matter what, we have to show personality."
1999 TREBLE
United remain the only English club to have won the treble, completing the feat under former manager Alex Ferguson in 1999.
They stopped Liverpool from winning all three trophies in 1977, winning the FA Cup final that year.
Ten Hag joked that he would not reveal the "key" to beating City, who lost 2-1 at Old Trafford in January.
"I won't tell you," he said. "I'll keep that for myself."
Ten Hag said he understood United fans' feelings about their unique achievement, issuing a defiant rallying call.
"We will do everything to give them it, to give them the second trophy, everything that I have, everything that the team have, the staff have," he said. "We will give everything to get that done.
"We can do it because we have proved it. It's not an easy job. It's a great team but we also have a great team and great players and we can beat them."