Manchester United academy products played twice as many minutes as any other side's in the Premier League last season.
A Press Association study using data available from Soccerway revealed that players graduating from the Red Devils' academy featured in a combined total of
"I think you have to go back to when Sir Alex first joined the club and overhauled the whole youth system," he said.
"He made sure there was a pathway for young, local players to get into the first team.
"From then on the youth system and that pathway to the first team has just got stronger and stronger, so when parents are picking a team for their son to go to and they want them to get to the first team, they pick United because you've seen over the years Man United give young players a chance.
"Then there is the coaching, the way they are looked after, the way first-team players look after the young players coming into the team. There's a number of reasons, but I think you have to go back 30 years ago to when it all started."