The defending champions are yet to bring in any new faces, but their title rivals Manchester United signed Shinji Kagawa and Nick Powell in June, while Roberto Di Matteo has added the likes of Eden Hazard, Marko Marin and Oscar to his Chelsea squad.
“We are a young team because we have played together for only two years,” Mancini told Sky Sports News.
“We won after 50 years. We need to work harder than last year and we need to buy the players that will help the team to improve.
“We don’t need big changes. We don’t need 10 players like maybe two or three years ago.
“But we need three or four or five players and in these five players will be young guys for the future because it is important to put young players in the squad and make them as good as the players that we have.”
The 47-year-old led the Eastlands outfit to their first Premier League crown last season, ending City’s 44-year wait for the top-flight title.
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