My GK under perfoms always in Big games..

[Hejst]

Like EastsiderSG wrote it's a key position (for me too). But that doesn't mean your goalkeeper is a key player. First you should find a good goalkeeper. Training a bad goalkeeper doesn't make him that much better. Good players get good ratings, even with lower quality. If you feel that your goalkeeper is letting you down in certain games, it's probably because he is, so change him to better one. Ratingswise I think goalie should always get at least 8, except for the matches you expect to lose (a lot stronger opponent).

Edit: Of course there can be bad days for goalies too. But they should be random and in a good teams there are others to cover up when needed.