IIRC, in one of the original drafts of Fate/Zero Dark Sakura was supposed to have a brief cameo in Kariya's death scene wjere she ends up completely rejecting him and everything he did for her sake(ie, while Sakura was still a little girl)......but even Nasu thought that was pushing it.
...only because Sakura hadn't been implanted with the Grail shards yet. :X