The 29-year-old, who has two Premier League titles in three seasons, completed his move to Old Trafford on Monday afternoon for a fee of £40m.
He was seen in good spirits during his first training session at Carrington on Tuesday and is likely to feature in some capacity against Sampdoria in Dublin.
And Irwin, speaking on the subject of Matic, believed that United have needed a player of his nature for some time.
“Matic is a player United have needed for quite a while. He’s also a signing designed to let Pogba off the leash a little bit,” he said.
The last attempt at signing somebody like Matic came in the form of Morgan Schneiderlin – a solid player who did well at Southampton but ultimately lacked a clear purpose when placed under the spotlight at Old Trafford. He always felt ambiguous – something perhaps not helped by the alacrity of Louis van Gaal‘s tactical decisions.
With Matic, however, United supporters know exactly what they are in for. And Mourinho, more importantly, knows exactly how to use him. He was drafted in from Benfica for a specific purpose at Chelsea and did it unfailingly in that second season which saw the Portuguese once again claim the Premier League crown.