Roy Keane
celtic by far
No, he left Manchester United in the summer of 2009 to join Manchester City.
Celtic because theyhave a solid team and have a solid line up so it would be celtic
It's your own personal opinion.
2008 ;D
No
Man united signed Wayne Rooney from everyton for 25 million
In England
Manchester Utd. have more combined wins than Celtic do since the first time they played each other , in which Celtic won the first match between the two.
Manchester United 1 (Rooney 12) Celitc 2 (Brown 24, Samaras 75)
Cristiano Ronaldo left Manchester United FC in 2009 for about 80million pounds to join Spain giants Real Madrid (A world record transfer fee) :)
Liam Miller was the last one, a free transfer from Celtic to Man Utd.