It all depends on the contract... if it's a full year deal then it goes on to the date in which you signed the contract, so Pellegrini would've had to been signed for the rest of the '10-11 season and 2 years after that for his contract to expire at the end of this season.
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Hope that's not confusing because I confused myself typing that up.
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Hope that's not confusing because I confused myself typing that up.