Otherwise - you could conceivably have a bloke who is second best every week. Win the Brownlow, but is not nominated.Come on, I don't think anyone can understand why you're making a big deal out of this! The rules for this award are quite clear, the nominees get named once (per year) and at the end of the year the judges work out who deserves to win.
Whilst those nominated have played one above average game for the season, albeit a blinder.