McTominay came through the ranks at Manchester United before making his senior team debut during the dying embers of 2016-2017 season in a Premier League game against Arsenal under Jose Mourinho.
The Scotland international has played 51 league matches for the Red Devils since his breakthrough.
McTominay’s importance to Ole Gunnar Solskjaer’s men was vividly seen this season, when he was injured for three months.
The 23-year-old returned from injury last month to help Manchester United mount an eleven-game unbeaten run, and scored a late goal in the 2-0 win against Manchester City.
Matic believes McTominay could become a vital part of Manchester United first team for the next ten years and insists the Scottish must work hard to improve every day.
"We are always talking, especially when he started to play in the first team, but now he's a proper senior player he plays like he’s had 10 years in the first team," the former Chelsea and Benfica man said on MUTV. "With him, we don't have any problems.”
"I think he will be a very important player for Manchester United in the next 10 years or more. He is the kind of player and person that you always want to have in the changing room.”
"[He is] very professional, with a lot of quality in the legs. His mentality is what Manchester United need to have, so I think that with any coach, in any club he will fit very well.”
"I'm happy for him and United that they have a player like that in the team. He just needs to continue how he's been working until now and I'm sure he will be one of the Manchester United legends one day."
