Carragher said: I think you've got to be honest and say what's happened at Chelsea will make a difference.
"The club with the most money can go and buy the best players and when you spend £50million you're going to have a stronger squad.
"They have improved their squad, but I thought it was quite interesting the other day when I heard Frank Lampard say how a few of the their lads were feeling a bit unsettled because so many players were being linked with their positions.
"I know myself, when you read in the papers about a player coming to the club in your position it can be a bit upsetting.
"Footballers talk about the situation, and if you think you're going to be sold, it plays on your mind. It hurts to say it, but Manchester United have proved over a number of years that continuity is the key to being successful, not just buying lots of players.
"They strengthen their squad but they've kept the same players who've played together since they were kids."
The Reds, of course, have also adopted a long-term policy for success, with the likes of Carragher, Michael Owen, Steven Gerrard and Danny Murphy expected to be the English backbone to the side for many years to come. Such continuity in the team will, according to the England international, prove vital in the forthcoming season.
"We still have the same lads here who helped us win the cup treble. And two years ago we got 80 points in the Premiership which would have been enough to win the league in most seasons, so we've not just become a bad team.
"At the start of last season we all thought we could win the league and those hopes just fell apart, but we were only one game away from a record-breaking start to a season. I think that proves we have the players here to do well.
"I think the main priority for us has to be to get into the Champions League now. We've got to aim for the title and push as hard as we can to win it, but realistically the target is to get into the top three.
"Don't get me wrong, our ambition is still to win the title and I don't think anyone can say that possibility is beyond us, especially with the good signings we've made with Harry Kewell and Steve Finnan. I just think it's going to be hard to do it.
"The signings we've made are good. Everybody who's seen them says the French kids are as good as anyone their age in the world.
"And without putting too much pressure on Harry, he's been brought here to add some creativity to our side, which is what we've been looking for."