North Melbourne coach Brad Scott has told Lindsay Thomas to ignore criticism that he ducks his head to milk free kicks and to keep challenging opposition tacklers.

Thomas received two free kicks for head-high tackles against Essendon last Friday night that prompted commentators such as Luke Darcy to suggest the small forward was not playing within the spirit of the game.

Scott publicly rebuked Thomas after an incident against Geelong in round 19 last year, when he won a free kick by feigning a push in the back from Cat James Kelly.

But Scott said on Wednesday he had no problems with the way Thomas was taking on tacklers, and had told the small forward so after the Bombers win.

"We have no issue with the way Lindsay's playing. In fact, I think Lindsay has improved over the last six years in terms of holding his feet in the contest," Scott said.

"We don't want him playing for free kicks as such but we do want him challenging the tackler and if the tackler doesn't employ the correct technique and Lindsay is able to draw a high free kick, so be it.

"We'll continue to get our players to challenge the opposition tacklers. It's well within the rules and the spirit of the game always has been (about) winning the ball in a contest and Lindsay does that really well.

"The spirit of the game to me is (about) the onus being on the tackler to lay a correct tackle."

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Scott conceded players who were able to draw high contact by lowering their shoulders or knees made it hard for umpires to adjudicate properly, but stressed the AFL umpiring department had made it clear that high tackles would continue to be penalised provided a player had not initiated high contact by ducking his head.

"If a player ducks his head and drives his head forward into the tackle that's a really dangerous practice and all players should be discouraged from doing that and the rules should support the tackler in that situation," Scott said.

"But that's the only situation (when a free kick should not be paid against the tackler).

"As for challenging the tackler in a high-tackle situation, everyone does it. It just so happens that there are some who are better at it than others."