The Hammers boss said the London club have raised their profile, while the players who made the trip to the US and Canada have also got sharper ahead of the Premier League season.
He was speaking after watching his side go down 3-2 defeat to a MLS All-Stars side in Toronto.
Curbishley, who's side had earlier beaten MLS side Columbus Crew 3-1 in Ohio, said: "The problem we had is that we have probably got five or six senior players missing from the squad tonight and the week we've had in America and now Toronto means, unfortunately, that some of the players here have had to play most of the football and I've not really been able to rest anyone.
"I was delighted to get through the game having picked up no injuries. All the clubs that come over for this game have done so in their pre-seasons and it's difficult for us.
"We're delighted to be invited. For us, we knew our profile in America and Canada was high, and it's got a bit bigger. We've enjoyed our week here."
He also believes the players who travelled on the trip will have benefited ahead of the Premier League starting again on 16th August.
He said: "We've got four weeks before we start, and we've left four or five senior players back home in London, had a couple of players here, (Craig) Bellamy and (Mark) Noble, who couldn't play this evening.
"We go back tomorrow and we know we've got a heavy three weeks or more coming up, with quite a few games, and it's a progression for us to build up to 16th August and the first game."