Ole Gunnar Solskjaer cited the example of Manchester United's famous Paris Saint-Germain comeback, in the wake of his side's Manchester derby defeat.
United were deservedly beaten 3-1 by Man City in the first leg of their Carabao Cup semi final at Old Trafford and will head to the Etihad Stadium for the second leg as huge outsiders.
It will be a huge task for United to overhaul the deficit, but Solskjaer spoke to Sky Sports after the game and referenced United's Champions League turnaround against PSG when talking about how United can bounce back. United were 2-0 down after the home leg against the French side last season, but won 3-1 in Paris to clinch victory via away goals.
"We've shown before that we've been down from a home tie and turned it around," Solskjaer said.
"Last year against PSG of course is the greatest example from us. We've just got to believe when we go to the Etihad that we can put a performance on."
In his post-match press conference, the Norwegian added: "We have to believe that we can put on a performance.
"Even though it's a steep mountain to climb, we can still climb it."
United will also need to draw inspiration from their 2-1 win at the Etihad in the Premier League this season, when an incisive counter-attack stunned Pep Guardiola's side. But City will be confident that they have one foot in the Wembley final with a chance of winning a fourth League Cup trophy in five seasons.
