Crotty, in Saturday night's 38-13 victory over the Wallabies at ANZ Stadium that wedged one meaty paw on to the prized Bledisloe Cup, suffered his sixth head knock in the last 20 months when he copped "friendly fire" from Jack Goodhue that coach Steve Hansen confirmed "knocked him out".
"I think if you look at the game, we still had three or four attacking opportunities after Maddocks scored to get us back within 12, with still 17-18 minutes to go".
Team-mate Sam Cane added: "It's not nice to see".More news: Nobel Prize-winning author VS Naipaul passes away at 85
"But it's actually not a long-term injury at all, just a lot of swelling."Everything else has a time-frame but there's just so much unknown with head knocks and it seems like you can be only one away, if it's the wrong one, from it being then end of it.
Shea Crotty, a top basketballer who has played for the Tall Ferns, tweeted: "I want to see my brother grow old and able, not battling the brain forever". "It certainly helps you appreciate every week and every game you have and realising how fickle it can be".
Hansen said he expected a better performance from the Wallabies in Auckland after they started strongly in Sydney but only to squander possession and succumb to a five-try blitz in the second half.
Australia, meanwhile, will be without star fullback Folau for at least the next match.More news: CNN accused of intimidating Paul Manafort jury
"It's true we haven't won there for a while but this is a moment in time where we've got to make the decision that it's not going to happen again".
"It's a lineout. Go and get it, win it, if you don't win it go get the ball some other how", he said.
"We'd be silly to think they haven't got another player who's going to step in and wear the jersey with pride and urgency", Hansen said.
"They had probably dominated that half so for us to get back in touch on the scoreboard was great".More news: Aguero scores hat trick, Man City crushes Huddersfield