Matic heaps praise on future Man Utd star
McTominay has made the breakthrough into Jose Mourinho's team, starting the last three games including crucial clashes against Sevilla and Chelsea.
The 21-year-old played alongside Matic both in Spain and at Old Trafford, and the Serbia international said he had tried to help his fellow midfielder get to grips with senior football.
"He is amazing," Matic said. "He is 21 and to play like that and control the game like that is impressive. He will be a big player for Manchester United.
"I like him because he is a very nice guy and he doesn't have a problem to ask before the game something and I am always there to help him.
"When I came to Manchester I saw within a few days that he would become a top player.
"He is working very hard, but I don't want to say too many things about him because he is still very young. But he deserves all the good things."