Ampadu was with Exeter City, where he made his first-team debut as a 15-year-old, before joining the Blues last summer.
Chelsea and Exeter couldn't agree on a compensation fee, and the issue was eventually resolved in court when the Premier League outfit were forced to pay £2.5m. But Morrison feels the amount should have been much higher.
"The kid's got it all," Morrison told Express Sport. "I remember the first day, he was 15, I thought to myself, you see this little kid with his hair and I always used to laugh about his hair and say: 'You need to get your hair cut mate, it's all over in your eyes'.
"But he came in and he was a natural. He looked like he'd been playing football for years, he looked like an accomplished 35-year-old. He's so comfortable on the ball, he was talking to the players in the training session.
"And he literally went back to school and we were driving home after training and I said: 'I swear that's Ethan Ampadu' and it was, he was walking back with his friends, no care in the world, after finishing doing his exams. That's what the kid's like. He's very level headed, he's grounded.
"I know Exeter only got £2.5m for him which I think is not right to be fair, because the kid is gonna be worth millions in years to come."