Former United man Butt said that the club will always promote homegrown players: 'I think the club won't allow for (there to be) no homegrown players,' he said.
Mourinho gave opportunities to plenty of homegrown players last season, including: Joel Pereira, Demetri Mitchell, Josh Harrop, Scott McTominay, Timothy Fosu- Mensah and Angel Gomes.
Marcus Rashford and Jesse Lingard also came through United's academy, before representing United at senior level and Butt is confident that more academy graduates will follow in their footsteps.
'We're fortunate that we've had managers that give youngsters a chance, but the academy staff can't be judged on who goes into our first team too much but they can be judged on developing players. That's what we pride ourselves on', he added.