I've found a pretty promising left-back to reinforce my team, but my scouts tell me that he doesn't relish the big occasions, so I guess his important matches attribute is low. What effect does it actually have, ie. is he bound to always play badly in big games (what count as big games? Finals of course, rival matches?) or just occasionally underperform? And is it possible that his important games attribute might improve (how?), as he is only 20 at the moment?