sold players can't play against us !

i know a loan player can't play but reckon this would be good
not seeing stevie tonight ,no even on the bench ,and bellamy on the bench but the only player not to get a start if i'm right in thinking ?, IF (more like when )we sell them is it possible to put in their contracts that they can't play against us this season ?does anyone know if this has been done before ?
it seems that when we sell a player he the "ex " player scores against us ,'i.e Dunne last year.............................it can also work in our favour i.e Ade,Tevez
it does seem though that nearly every team we've played over the years i've been watching city where an 'ex' blue is playing he seems to score
any thought lads ?
not seeing stevie tonight ,no even on the bench ,and bellamy on the bench but the only player not to get a start if i'm right in thinking ?, IF (more like when )we sell them is it possible to put in their contracts that they can't play against us this season ?does anyone know if this has been done before ?
it seems that when we sell a player he the "ex " player scores against us ,'i.e Dunne last year.............................it can also work in our favour i.e Ade,Tevez
it does seem though that nearly every team we've played over the years i've been watching city where an 'ex' blue is playing he seems to score
any thought lads ?