This is a situation no one would like to find himself in because it might leave you with a headache. As a manager, from time to time, you should try out your academy players on the field to give them a little bit confidence. Also, you should be rotating your squad more to reduce fatigue and to solve certain situations like this. Rangnick did very well when he was frest in Manchester United by playing most of the academy players in a champions league match.
when faced with such situation, because i will be a regular rotator of my squad, it wouldnt be difficult using my reserved players. Also, i will be trying out my academy squad from time to time so in this situation, because they have a little bit confidence, i believe they will play with confidence.