The 30-year-old retired from international duty after last season's Asian Cup in an effort to prolong his club career.

And the reward is a contract extension Ferguson expects the South Korean to sign.

Meanwhile, Ferguson has confirmed new keeper David de Gea will start Saturday's friendly with Chicago Fire at Soldier Field.

The 20-year-old was a late arrival on tour after a successful European Under-21 Championship campaign in Spain.

He has trained for three days now and Ferguson wants to see how he performs in a match environment, believing the £18million signing from Atletico Madrid may draw comparisons to Chelsea's Petr Cech.

"David de Gea will start on Saturday," said Ferguson.

"He has had a few days' training now and has done fine.

"Being young and coming into the English game, the one area we are not sure about is that he may need time.

"On the other hand, he might do what Petr Cech did at Chelsea and take it by storm. Cech came into the Chelsea team and has never been out of it.

"David has similar qualities. He has terrific composure for a young man. He is quick. His use of the ball is excellent.

"There are good ingredients there. Hopefully that shows itself as we get into the season."

United flew into Chicago fresh from their 7-0 thrashing of Seattle Sounders.

However, they are going to encounter very different conditions now as temperatures topped 100 degrees Fahrenheit on their arrival.

No reduction is forecast and with the game set for a 4pm kick-off local time this weekend, Ferguson admits he will have to adopt special measures.

"We have left a cool atmosphere in Seattle and arrived in a furnace," he joked.

"It is going to be a test. We prepare for things like this but we will probably reduce the length of our training sessions and make the appropriate changes.

"I don't think it is forecast to get any cooler, so maybe I will watch the match in the hotel."