The Colombian is the most potent striker in the country with 23 goals but he plays on the edge and is prone to react when challenged by defenders.
McAllister, who has compared Morelos to Eric Cantona and Wayne Rooney, says Rangers are working every day with him to curtail his explosive nature.
Centre-back Connor Goldson also reckons Morelos has to cool it, but insists rival defenders are out to get him.
McAllister said: “He’s a target. He’s the top scorer in Scotland and defenders are going to try to get close to him. That plays into his hands because, if it becomes a bit of a wrestling match, I wouldn’t want to take him on.
“We can’t avoid it because part of his game is getting involved and feeling defenders so what he has to try to do is not over-react when someone gets too close or too aggressive.
“He can’t react. He has to take this close attention as a compliment.
“There was quite a big French lad [Cantona] that came to Leeds who had that sort of thing. I don’t need to talk about him do I?
“I don’t want to equate Alfredo to any other player but there are many who play like that.
“He’s a very competitive player. The physical side is a big part of his game. I remember when Wayne Rooney was younger, he got involved when he thought he was on the wrong end of decisions that were made because of his previous.
“So we are working and trying to improve the disciplinary side of his game, but it’s a very fine line. Now that we are getting to know him the facts are, we have noticed some little improvements in recent weeks.”
McAllister feels Morelos’s previous record came into play when Bobby Madden sent him off in Wednesday’s 4-2-win at Aberdeen, in which he scored two goals, when he and Scott McKenna clashed.
McAllister said: “I think his reputation slightly influenced that. I have watched it from every angle. There is a wrestling match and two competitive players trying to get the ball. The position the pair get into is awkward and I don’t know where Alfredo can put his legs. They’ve gone up and they’re coming down.Was there an intentional stamp? I don’t see it.”
Goldson says the dressing room is right behind Morelos. He said: “The centre-halves in this league kick him all day and are physical with him. When it gets to a stage where every time he is going for the ball they are pushing him in the back, grabbing his shirt – you find it hard not for him to react.
“They do that knowing there is a chance he will react. They try to push him literally to the limit every single game.
“They try to get our main goalscorer sent off. It is something he is going to get and he needs to learn he is such a target. But, the boy has scored 23 goals for us and has won so many points on his own this season so we are not going to hammer him in the changing room.”
Goldson is hoping Rangers can make it a hugely successful week by defeating Kilmarnock at Rugby Park to win a place in the quarter-finals of the Scottish Cup tonight. He confirmed that Aberdeen tried to wind Rangers up last Wednesday night by placing photographs of their League Cup semi-final win along the walls of the corridor en route to the dressing room but it merely added to Rangers’ motivation.
Goldson said: “I don’t know if their thinking was that it was going to bring us down, or we would look at them and get emotional before the game, but we looked at them and it gave us more motivation before the game.
“We have shown in the first game this week what we are about. Now we go into another massive game and we need to put in the same performance, the same energy and reach the same level.”