The Spanish defender penned a four-year-deal with Barca, where he initially graduated as a youth player.

Spanish reports suggested that the 21-yaer-old was bought for around €14M, even though the transfer fee was not announced.

Pique struggled to break into Alex Ferguson's selection at Old Trafford, as his presence was overshadowed by the fine form of Rio Ferdinand and Nemanja Vidic.

The highly-rated defender is Barcelona's second recruit this week, following the signature of Mali midfielder Seydou Keita from Sevilla.