"It is going to be tough to win the league this season, tougher than it was last year," said the
"We know just how hard it will be. Everyone will improve. But we are desperate to win it again and feel we will be better ourselves.
"Once you win one trophy, it is not so much that you want to win more, it is that you expect to."
Despite the new signings Carrick knows what is expected of him to not become a victim of Tinkerbell.
"The manager has not said anything to us yet about the way he intends to use us all," said Carrick.
"At the moment, we are just trying to get as fit as we can.
"It doesn't really matter anyway. Regardless of who has signed this summer, you have to be at your best to play for Manchester United.
"The more world-class players we have the more it will benefit us.
"It is a long season and we will be playing a lot of games.
"There will be times when you are out of the side. But when you are in, you will have to play well.
"Everyone is raring to go. There is a big challenge out there for us this season."