Manchester United midfielder Darren Fletcher found the team's four-day training camp in Chicago tough going but believes it will help him in the long run.
Fletcher cannot wait to face Celtic on Friday night at Toronto's Rogers Stadium in United's first pre-season friendly, after working up a sweat this week.
He said: "We are excited about the game as we have completed 10 days of pre-season training. Being Scottish, Celtic is an interesting match for me. Training has been difficult but I am sure we will feel the benefits once the season gets under way."
Fletcher added: "It was hot enough in Manchester but the heat and humidity in Chicago was something else. It takes a little bit more out of you in training.
"But it is good preparation for what lies ahead and it was great visiting Chicago."
United's travel plans were thrown into chaos after the party were delayed from leaving the city because of bad weather.
Manager Sir Alex Ferguson was unaffected by the disruption as he left Chicago early to attend a private dinner in Toronto.
Fletcher believes the manager will use the majority of the 22-man squad against Neil Lennon's side, given it is their first game.
The 26-year-old said: "You have to be careful as you are not accustomed to playing 90 minutes as your body has had a rest.
"So I would not be surprised to see the minutes managed by the coaching staff. I can see players perhaps playing 60 minutes or half a game with a lot of changes. It means everyone will get a fair share of playing time."
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