Manchester City seal Johnson deal
The former England U21 international - who won 19 caps, scoring four goals - has agreed a contract with the Blues until 2014, and will wear the number 11 shirt.
The 22-year-old, who fell four games short of making a century of league appearances for Boro, has almost single-handedly kept the Teesiders' promotion hopes alive this season - netting 12 goals in all competitions for Gordon Strachan's side.
"We are delighted that Adam has chosen to come here. He is a very good player with fantastic potential, and as a club we are always keen to sign British talent," the Blues' boss Roberto Mancini told the club's official website.
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