Ole Gunnar Solskjaer’s side missed out on a place at Wembley as goals from John Stones and Fernandinho secured a 2-0 win for City at Old Trafford on Wednesday evening.
Fernandes has now lost three semi-finals since he joined United last year as Solskjaer’s side were beaten by Sevilla in the Europa League and by Chelsea in the FA Cup.
And the Portugal international has urged his United teammates to ‘learn’ from their latest setback.
‘I’m very sad and disappointed to once again don’t reach a final,’ Fernandes posted on Instagram.
‘We have a lot to fight yet but we have to learn and understand that we can’t make the same mistakes anymore.
‘We need to make an effort to further improve and be able to fight for trophies!’
Solskjaer, meanwhile, defended Fernandes following his below-par performance against Pep Guardiola’s side.
‘Well of course it’s not just about Bruno not finding inspiration. It’s the whole team that should create chances,’ said the United manager.
‘When you play against good teams – I thought Man City played well tonight – you have to be spot on.
‘Anthony had a couple of half-decent ones, but we just didn’t have enough in either the last pass or the last finish.’