Marcos Lopes, 17, struck for City in their FA Cup win over Watford on Saturday.
Platt said: “It’s a reflection on ability. Roberto made his Serie A debut at 16 because he had ability in abundance – perhaps a bit too much of it at times! It is nothing to do with age with Roberto – he talks about the ability, and he was not worried about putting kids on the bench.
“Quite apart from that, the manager is happy to go with young players as and when he needs to.”