Levi Greenwood thought he could be on his last chance at North Melbourne when he got a call up for the round two clash against the Western Bulldogs.

From day one of the 2014 pre-season, Greenwood had been mindful that this season was the last of his existing three-year contract.

When the bullocking midfielder signed that contract in June 2011, he had, when fit, been an automatic selection in the Roos' team for two-and-a-half years.

It was a surprise, then, when he was overlooked for North's round one clash with Essendon in 2012, but that was just the beginning of his fall from grace.

Greenwood would play just five senior games that season and none after round 12, while his transformation from senior to fringe player seemed complete last year, when he managed only six games.

At times in 2013 he was the Greenwood of old. In round 15 he blanketed Richmond skipper Trent Cotchin and in round 21 he ran rampant against Essendon's midfield, racking up 39 possessions in a best-on-ground performance.

But after both matches he was dropped one game later.

When he returned to training at North's Utah camp last November, Greenwood just wanted to have a "really big pre-season".

But foot soreness troubled him over the summer, which meant he entered 2014 slightly below full fitness.

He was not selected in North's three pre-season games either, but good form with VFL affiliate Werribee and the Roos' dismal round one loss to Essendon conspired to give him his opportunity.

Not surprisingly, Greenwood was nervous when he was named as North's substitute against the Bulldogs.

"It's a long season, but there were some thoughts at the start of the game that this could be my last chance," Greenwood told AFL.com.au this week.

"I was thinking, 'This is my chance to step up and, hopefully, if I play well in the sub role I'll get a full game next week'.

"It was at the front of my mind at the start of the pre-season that I was coming into the final year of my contract.

"And I don't want to get delisted, I don't feel like I'm done yet."

Greenwood grabbed his opportunity against the Bulldogs in the same way that he bores into a contest – with single-minded vigour.

Despite not being substituted into the game until early in the final quarter, he had 13 possessions, three clearances (including two at centre bounces) and kicked a goal to help the Roos stretch a precarious 10-point three-quarter time lead into a relatively comfortable 29-point win.

When co-vice-captain Jack Ziebell was a late withdrawal from last Sunday's game against Port Adelaide, Greenwood stepped up to share the inside load at stoppages with Ben Cunnington.

Although Cunnington deservedly received most of the fanfare after the game for his best-on-ground performance, Greenwood was his partner in crime.

The 25-year-old South Australian finished the game with a game-high 34 possessions, an equal team-high six inside 50s, six clearances and seven tackles.

His performance was recognised by North coach Brad Scott and his Port counterpart Ken Hinkley, who together gave him seven votes in the AFL Coaches Association award, second only to Cunnington (10).

Greenwood said this week the past two seasons had been tough.

"A few years ago, I was getting picked most weeks and I thought that was the way it was going to continue," he said.

"But the way the team played changed and my form wasn't quite as good as it was a couple of years ago, so I had to spend some time in the seconds.

"It's made me work harder and it's made me appreciate the time I do have back in the senior team now."

Given he's been dropped four times in the past two seasons, Greenwood does not need to be told he could lose his senior spot just as quickly as he won it back.

He says concentration lapses, which saw him drift away from playing his designated role, have hurt him in that time.

But he is determined he won't make the same mistakes again this year.

"We move on quickly. What happens a couple of weeks ago is soon forgotten; you're only as good as your last game," Greenwood says.

"I think my competitiveness is why Brad puts me in the side, especially with Jack (Ziebell) and 'Spitter' (Andrew Swallow) out.

"We need that strength in the midfield and that's what I'm going to try to bring in the next few weeks and, hopefully, I can hold my spot when 'Ziebs' and Spitter come back.

"I'm not going to let it go now."