The Lions concede 20.8 free kicks per game and have the worst differential (-3.6) of any team in the league.
They have also had five players suspended, and another five reprimanded.
A staggering nine players are ineligible to win the Brownlow Medal – four more than any other club.
Rockliff said the Lions were reckless on occasions – conceding free kicks and suspensions - and would need to revisit their technique in the off-season.
"We probably haven't done a lot of tackle technique stuff this year, or not as much as previous years," Rockliff said.
"Players are smart and know how to make it look like they should be awarded a free kick. You've got to be so careful and make sure your technique is so perfect.
"I'm sure we'll be doing some work during the pre-season on that."
Co-captain Jonathan Brown, Daniel Merrett, Dayne Zorko, Jack Redden, Matthew Leuenberger, Ash McGrath and Andrew Raines are all in the AFL top 40 for most free kicks conceded.
The Lions have lost eight successive free kick counts, and 13 of 18 in total, including a 19-7 hiding from the umpires against St Kilda last Saturday night.
"It's concerning when you're losing the free kick count consistently and by quite a little bit," Rockliff said.
"It's concerning (that) it's so lopsided, and we have to look at it and the way we go about it.
"We've got to look to clean that up."
Key personnel Brown, Merrett, Pearce Hanley and Mitch Golby are among those who have been suspended.
While Rockliff said a couple of those were "borderline", the fact was the Lions have missed important players in too many matches.
"You've got to be so careful these days, there's so many cameras," he said.
"It's probably the silly ones where blokes are swinging arms and hitting blokes in the head, and the reprimands are a bit concerning. We've got to act on that and improve.
"If you're giving free kicks away or not having your best team available it's a concern for the footy club."
Michael Whiting is a reporter for AFL Media. You can follow him on Twitter: @AFL_mikewhiting