Rooney was fuming 'one of the reserve players' had nicked the phone charger he was using in the Carrington dressing room.
He told the Utd Podcast: "I remember I smashed his phone up at one point.
"He came in the first team dressing room when he was in the reserves. My phone was on charge and he took it off and put his on.
"It was when we had the old BlackBerries and it had the email address on the front.
"I thought it was one of the other lads so when I saw it was one of the reserve players I just smashed the phone up!"
Rooney cited Morrison, now 27 and at Dutch club ADO Den Haag, as the biggest disappointment not to make the grade at Old Trafford.
He added: "With the younger players it's been well documented about Ravel Morrison.
"He was brilliant in training and then he had a few issues and it halted his career.
"We all thought he was going to be top level. Everyone could see those issues were going to be there. I spoke to him.
"Gary Neville was trying to get him to live with him. There were different things people tried."