The 19-year-old joined Blues on a season-long loan from West Ham and has quickly made an impression in the Championship.
Morrison scored his first senior goal on Saturday, a superb volley against Hull, and McDermott says he has what it takes to cut it with the very best.
"He's a great talent," he said. "I know he's got a reputation but he's a great kid and he wants to do well here. He loves being here and wants to be involved.
"He's got the ability to go right to the top and he will do if he listens to the right people, like the manager and the coaching staff. We've all helped him but we know there's more to come.
"He is thriving on the pressure. He should score more goals with the ability he's got. He scored a fantastic goal Saturday and long may that continue."