NORTH Melbourne is confident Nathan Grima will be available for the start of the season despite the key defender breaking his right little finger at training last week.

Grima, who is expected to be sidelined for five weeks, will have scans on Wednesday to determine whether surgery is required to repair the finger, which has been immobilised in a guard to keep him from moving it.

Club doctor Con Mitropoulos said that because Grima had fractured the finger at the knuckle joint, extra care had to be taken with its treatment.

"It's not going to change the timing of it if we operate or don't operate," Mitropoulos said. "The only reason to operate is if it looks like it's moved in the last week.

"The good thing for him is that on the [initial] x-ray it's in a good position.

"If his [next] x-ray's good tomorrow (Wednesday), then we won't need to operate to put any wires or screws in it."

Grima should start running towards the end of next week with a view to building into full training by the middle of March.

Mitropoulos said all that could prevent Grima from pushing for selection come round one was if the finger still felt uncomfortable when punching or grabbing the ball.

"It should be very strong," he said. "Whether we operate or not, it should be right by then.

"They usually heal extremely well if you're careful with them for the first five weeks. There should be no ongoing issue.

"The only risk with trying to get them back that quickly is that if you put a wire in there, it fuses the joint for the first few weeks and it's harder to get going. It's harder for him to handle the ball and make a fist.

"Even if he has some soreness, as long as it's safe for him to be playing, he'll be playing."

Before the injury, Grima had been one of North's better performers of the pre-season, completing every session and winning the club's first two time trials.

Grima said he would push to return for the fourth week of the NAB Cup competition, or play at a lower level on the bye weekend if that couldn't happen.

"I'll definitely be ready for round one. Whether or not there's a spot in the team for me, that's another story," he said.

"To not miss a session and then get injured was very disappointing. But I just think back to two years ago when I had a knee reconstruction ... so there's no point moping around."

The 24-year-old made his debut in 2009 and emerged as North's preferred option at centre half-back in his 13 games.