NORTH Melbourne forward Aaron Edwards believes he is in the best physical shape he's ever been in, and he owes it all to a misdiagnosed thumb injury.

The 25-year-old initially hurt his left thumb mid-season but waited until the end of the Kangaroos' year to have the injury fully assessed.

When x-rays failed to reveal any serious damage, the former Eagle went on his end-of-season holiday and tried to forget all about it.

However, when he returned to Arden Street, the persistent pain led him to have a CT scan. It showed a chipped bone and frayed ligament, and Edwards was booked for surgery. 

"We tried to figure out what it was but we couldn't quite put our finger on it," he recalled.

Edwards had the ligament repaired and a wire inserted on November 19.

He is now a week away from having the plastic thumb cast - and the wire - removed.

Since the operation, he has been boosting his cardiovascular fitness with fellow hand-injury recipient Liam Anthony to the extent where he is in tip top shape.

"We've been getting a lot of cardio in. It's given me a chance to really build a good foundation for next season," he said.

"I'm lighter than I've been since I've been to the club and I'm running better times in all the time trials.

"I feel that I'm in better shape than previous years so I've got to keep on going in that direction."

Edwards aims to get a couple of full training sessions in before the Kangaroos commence their festive break.

He also believes he is a definite starter for the club's NAB Cup campaign, which commences against Geelong on February 21 at Etihad Stadium.

"After Christmas I'll be back into full training and it will give me some good solid weeks to build up," he said.

"The fitness is there so I'll just have to work on that."

Edwards said he was intent on making up for his previous pre-season transgressions, the latest of which saw him suspended from the club's 2009 training campaign and their first four games after he was caught speeding.

He later lost his licence for four years. He was also fined $1500 for refusing a breath test at the time of the incident.

It was his second drink-driving offence, and came two years after he was fined by the club for being drunk at a Lionel Richie concert. 

"I got another contract so they showed a bit of faith in me there and I've got to do the same going the other way," he said.

"So far this pre-season I've been working really hard. I had a bit of a mishap with the thumb but other than that, I'm putting my best foot forward."