The 25-year-old almost joined Manchester United after he attracted attention from the World Cup.
"I think it's very important," said Morgan.
"His first season was last season and he had a fantastic season, he got the player of the year award and he rightly deserved that as well.
"I just want to see him progress, continue to improve and become the great player I know he's going to become.
"Ever since he's come in, he's been a revelation. I think he's settled in so well, for me he's just got better and better.
"The more his confidence has grown, he's stepped into the England set-up and it looks like he's been a part of that set-up for years.
"The confidence he has on the ball, the way he starts attacks, he's got a lot of attributes for a big central defender.
"He's had a lot of attention on him over the summer, over possibly going to other teams, but I'm glad he's stayed here."