Carlton forward Jack Martin will also face video scrutiny for his high hit on Sydney's Nick Blakey early in the Friday night elimination final, which the Blues won by six points.
Blakey left the field immediately after the incident, but returned and played out the game.
Brayshaw will miss Melbourne's semi-final against either Carlton or Sydney under AFL concussion protocols after he was flattened by Maynard less than 10 minutes into Thursday night's 9.6 (60) to 7.11 (53) loss at the MCG.
Maynard jumped towards Brayshaw, attempting to smother his kick inside 50, and turned and collected the midfielder high with his shoulder, knocking him out cold.
Brayshaw required lengthy attention on the field before leaving the field on a stretcher and in a neck brace.
AFL match review officer Michael Christian graded the act as careless conduct, severe impact and high contact.
He is facing a ban of at least three matches at the AFL Tribunal.
Jacob van Rooyen was also dealt bad news, with the young Melbourne forward handed a one-match ban for a striking offence.
Van Rooyen collected Daniel McStay on the jaw with his arm after the Magpie dropped a mark in the first quarter and the ball spilled between them.
The Magpie went off the ground for a concussion assessment but returned and played out the game.
The incident was assessed as careless conduct, medium impact and high contact, drawing a one-match ban.
It means van Rooyen will miss his team's semi-final unless Melbourne successfully overturn the decision at the AFL Tribunal - should they choose to challenge it.
And unless Collingwood's lawyers can successfully downgrade one of Maynard's classifications, he will miss the Magpies' preliminary final - and grand final should they make it that far.
"I don't want to say too much, but it's a footy act," Maynard told the Seven Network after Collingwood's win over Melbourne.
"I came forward, I jumped to smother the ball and yeah, unfortunately I just got him on the way down.
"So I don't know. We'll have to wait and see what happens."
Melbourne coach Simon Goodwin certainly wasn't doing Maynard any favours.
Brayshaw, 27, cannot play again for at least another 12 days, while he has a lengthy concussion history and wears headgear.
"I guess that'll be sorted out during the week, but we've got a pretty shattered player (Brayshaw) in there," Goodwin said.
"Look, you can only go by the facts: he jumped off the ground and knocked a guy out.
"So I guess time will tell."
Beyond the concussion, Goodwin said Brayshaw only had a "shiner".
Collingwood coach Craig McRae queried whether there was malice to Maynard's action.
"I've caught it on a phone. One view of it, one angle, it looks like he's in the air," he said.
"The act itself, it didn't look like it had much malice but I'll leave it up to others to decide if that's worthy of a suspension or not. I don't know."
Immediately after the Blues' 11.8 (74) to 9.14 (68) win, Martin told Channel Seven that when he went to the interchange bench following the Blakey incident, coach Michael Voss told him "good tackle".
