However, a nasty ankle injury sustained in his country's opening match means the winger will play no further part.
And, whilst he does not believe the problem is serious, Ferguson is taking no chances and has told the player to head back to United's training complex for treatment.
"Antonio has gone straight back to Manchester," said Ferguson after the 4-1 win over New England Revolution in Boston.
"He got an injury playing in the first game for Ecuador so he is back in Manchester.
"It is nothing serious but he wasn't going to be taking part in the rest of Copa America, so there is no point in him coming out here if he is injured.
"We have the facilities back at Carrington. That is the best place for him."
It was a long-term ankle injury last season that persuaded Ferguson to head into the transfer market this summer to secure a reinforcement.
The chosen man, Ashley Young, made his debut in front of 51,000 at the Gillette Stadium, producing a number of decent crosses from his wide role and showing enough signs to suggest he will have no problem settling into his new surroundings.
"That was his position until last season when they started playing him behind the strikers in a more advanced role, like the way we use Wayne Rooney,'' said Ferguson.
"His capabilities are such that he can play at wide left, he can play in behind the strikers and he can play wide right.
"He showed tonight he's a fantastic crosser of the ball. I think he hit three fantastic crosses in the game, which maybe isn't something we're used to with the way we play.
"But if we do get used to it then there's goals there. I was very satisfied."
After a goalless first half, Michael Owen broke the deadlock just after the break.
Teenage striker Federico Macheda added two more, with Park Ji-sung wrapping up a comfortable win.
United now head to Seattle for a week-long stay, being joined by chief executive David Gill on Friday.
Gill was at a European Club Association meeting in Zurich on Wednesday, which would have provided an opportunity to speak with Inter Milan about the possibility of signing Wesley Sneijder.
There is nevertheless a growing feeling Sneijder is Old Trafford-bound although, with Gill now heading across the Atlantic, any transfer may not be completed for a little while yet.