Erik ten Hag splashed £42m on the Uruguayan star this summer as he looks to redesign and reshape the club's midfield which has been the source of a number of problems in recent years.
The former Paris Saint-Germain midfielder missed the Liverpool game in which United were torn apart by their biggest rivals.
Ugarte could be the difference maker in this United squad that desperately needs a leader and he spoke about how ready he is to take up his new role.
“I’m very happy, very hungry and very excited.
“I feel very good, the truth is that I haven't played many minutes since the season began, but physically I feel very good.”
Ten Hag spoke about Ugarte and his fitness levels over the last week.
“It will take time.
“If you see Manuel Ugarte, he didn't play so far in the season. Not one match minute. So he needs to build his fitness and then we have to build him in the team and I'm sure he'll be an important player. But that will take a couple of weeks, maybe even months.”
Uruguay face Paraguay and Venezuela in the coming weeks in their World Cup qualification run in which Ugarte could build up a level of fitness ahead United’s clash against Southampton.