Morrison made his first Premier League start in Sunday's goalless draw at Southampton.
And Jaaskelainen said: "He is a very talented young boy who has really come through over the last season. He was on loan at Birmingham and he played regularly - that's the main thing when you are young player. You have to go and play games.
"There is no point going to a big football club and sitting on the bench, if you go to the lower leagues or the Championship, it is very good to get that experience in games and get better. You can see the benefit of that now.
"Talent-wise, he is absolutely brilliant and hopefully he can take into the game what he does in training and start performing at that high level."
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