Skip columns on validation process

Is there a way (or what is the way) to skip fileds on validation ? I have a virtual foreign key that it is failing: Value of field "match_winner" does not exist on referenced table. So i want to skip this field if it is not set. I can not do this on init because the object is empty.


Thank you but no, this will not help. validation process is triggered after initialize(). And i need to skip attributes depending on certain values.