North Melbourne Kangaroos coach David Noble has been left frustrated by his team's ill-discipline in the opening round loss to Hawthorn at the MCG on Sunday.

The Hawks won by 20 points after the Roos held quarter-time and half-time leads, and Noble said his players giving away crucial free kicks needed to be looked at.

HAWKS v KANGAROOS Full match coverage and stats

"To their credit they (the Hawks) got that range of unanswered goals and then we were undisciplined and that's just got to be addressed," Noble said.

"That is not good enough."

Noble said a crucial patch in the third term hurt his side dearly.

"We had that seven minutes ... five free kicks and two 50s. Cal's (Coleman-Jones) having a shot at goal and Nick (Larkey) gives away a free kick," he said.

"I understand you're getting into the hustle and bustle, but we know damn well how the umpires are umpiring. We know the difficulty that umpiring is, so you shouldn't just give anyone, certainly the umpires an opportunity to pay a free kick against you ... we're having a shot on goal.

"We've got to get better than that."

Noble said the Roos needed to capitalise when they had the game on their terms during the second quarter.

"I was a bit disappointed, but also really encouraged. We were 21 points in front … had we been a bit cleaner with the ball, we might have been able to stretch that out," he said.

"We’ve got to be careful and we’ve got to be balanced in how we approach it.

"I thought they showed some really good signs; when we got the ball, the way we wanted to move it.

"We probably had the game on our boot for a lot of the length of the game, but they took their chances and we probably didn’t."

Noble was full of praise for No.1 draft pick Jason Horne-Francis, who showed glimpses of brilliance in his 13-disposal, one-goal debut.

"Yeah, [he was] terrific … just the balance of midfield time and forward … he can actually add some firepower for us down forward, but he will want to play all of his game in the midfield," he said.

"He showed some real class at times; he was clean off the deck, his power to come away from a contest to get to the next one … yeah, it was pretty impressive."

North will be missing key defender Ben McKay (concussion) for its round two clash against West Coast on Saturday night.

"He’s fine, I don’t think he’s unwell, as far as a concussion; he’ll just fall into the normal protocols," Noble added.