The Uruguay international was the last of the first-team summer signings for our men, sealing his switch from Paris Saint-Germain on transfer deadline day.
After being presented to the Old Trafford crowd before the game with Liverpool in the Premier League, our new no.25 is currently away in South America representing his country in the World Cup qualifiers.
There is great anticipation of seeing him pull on the United shirt for the first time and Butt is convinced he will have a key role to play under Erik ten Hag this term.
Speaking to club media after taking part in the Legends game against Celtic at the weekend, Butt said: "I've seen a bit of him last year and I think he's what we need.