"Thanks for everything, Boss." Cristiano Ronaldo on Twitter. (Note: Adjoining image courtesy Ronaldo's official Twitter account)
"2001-2006, 219 games,150 goals under the most successful manager in football history. It was a unique privilege." Ruud van Nistelrooy on Twitter
"His achievements in the game place him without doubt as one of the 'greats' ... Will his longevity at the top ever be repeated?" - FIFA President Sepp Blatter.