Players that have played for Manchester United, Manchester City, Liverpool, Everton, Celtic and Rangers. Obviously.
Duncan Ferguson, alex cleland, Andy gray
roy of the rovers
The answer is Paul Gascoigne, he has also played in derbies in north london, merseyside and rome
There is only 1 player that has played in a Manchester Derby, Merseyside Deby and Old firm Derby and that was Andrei Kanchelskis (possible wrong spelling). This player played for Man Utd, Everton and Rangers. I don't believe any other player has managed this feat.
Andrei Kanchelskis, for Everton, Rangers and Man Utd.