A spate of rough-conduct suspensions and concern over concussions led to the AFL issuing a memo to clubs this week clarifying its position on dangerous tackles.
Hardwick says players, coaches and umpires could all do more to reduce the risk of injury.
"It is a bit of a grey area at certain stages," he told reporters on Saturday.
"Some of those things have been cleared up ... it's like a bigger conversation needs to be had.
"There's a combination of factors that we need to sit down and figure out.
"The players absolutely have got a responsibility to look after the head when they tackle, but there's other factors at play.
"One, coaching for us. Also, the administration from the AFL with regards to holding the whistle needs to be a little bit clarified.
"We don't want players getting hurt but we want to make sure we understand the players have got a really, really tough job to do."
Essendon skipper Zach Merrett and Collingwood vice-captain Taylor Adams are among those to fall foul of the clampdown, with both missing the traditional Anzac Day blockbuster through dangerous-tackle bans.
Brisbane Lions coach Chris Fagan said he understood the AFL's desire to reduce the risk of injury but remained sympathetic to the tackler, particularly when a larger player comes up against someone smaller.
"How could our players not be aware? It's been the case for quite a few years, the AFL is clamping down on dangerous tackles," Fagan said on Friday, adding that most dangerous tackles are not intended to be that way.
"It's really difficult to coach the players not to tackle with vigour ... you've got to do that with an element of aggression," he said.