Barcelona's Gerard Pique, Fiorentina's Giuseppe Rossi and Portland Timbers' Mikael Silvestre - all former Manchester United players - have paid tribute to Sir Alex Ferguson on Twitter:
26 years, 13 league titles, 2 Champions Leagues, the Cup Winners' Cup, 5 FA Cups, 4 League Cups… Legend! http://t.co/33SRUiu0B3
Sir Alex Ferguson's brisk way with words has influenced the way we talk about football.
A timeline of the life of outgoing Manchester United manager Sir Alex Ferguson.
A special photo gallery of Sir Alex Ferguson's career at Manchester United as he steps down from his post as manager of the club.