Kennelly had to be helped from the field late in the game after being hit by Dawson from behind in a marking contest. He vomited after the match and was still suffering headaches on Sunday morning.
Roos said the match review panel’s verdict on the Kennelly clash appeared to defy the league’s decree that players’ heads were sacrosanct.
“I thought it was made clear that any collisions to the head were going to be looked at seriously,” he said on Monday afternoon.
“I don’t know whether that’s changed, or whether in that particular incident it was deemed that Dawson went to mark the ball, I’m not too sure.
“I think everyone was on notice that guys' heads were to be protected, but it’s more up to the match review panel to comment than me.”
Dawson’s teammate Justin Koschitzke faces a three-game ban for a bump on Nick Malceski that left the Swan defender dazed in the opening minute.
Despite the apparent contradiction, Roos said he would continue to direct his players to keep their eyes on the ball and attack each contest with vigor.
“You can’t be responsible for players from other football clubs,” he said.
“When we’re talking to our players, [we tell them] as long as your eyes are on the ball and you’re going for the ball, as long as you do that, you’re fine.”
Roos said Kennelly and Malceski would be rested from training early in the week but he expected both to be fit to face Adelaide at AAMI Stadium on Sunday afternoon.
After viewing the replay on Monday, Roos was pleased with his team's endeavour against an opponent widely expected to challenge for the premiership.
"I think people have sort of underestimated, surprisingly enough, how good St Kilda are," Roos said.
"While we started four weeks earlier, they had some really good game time into their players so it probably took away a little bit of the advantage you were hoping to get against a grand final team.
"They won 19, 20 games in a row last year and obviously played in the grand final and were really stiff to lose. We've got to be really pleased with the way we went about it."
However, the ease with which the Saints scored several goals from deep within their forward 50 is still a sore point for Roos.
"Probably our most experienced group is our defensive group and you're less forgiving with them at the moment," Roos said.
"That defensive group has been around for a fair while and I just thought the number of easy goals we were letting in really hurt us and at the end of the game, it sort of cost us the game."
