Melbourne coach Simon Goodwin says it's time for his AFL reigning premiers to rediscover their best form, starting against Port Adelaide.

Melbourne coach Simon Goodwin has a blunt message for his AFL reigning premiers: the time is now.

The Demons meet Port Adelaide in a nominal home game in Alice Springs on Sunday amid a worrying dip in form.

While still sitting second on the ladder, Goodwin's charges have lost four of their past six games.

And the fixture against the 12th-placed Power starts a testing run into the finals, with games against the Western Bulldogs and four probable finalists - Fremantle, Collingwood, Carlton and Brisbane - to follow.

"The challenge is right before us as a footy club," Goodwin said.

"We feel like there's still a lot of growth and a lot of improvement in a whole range of different areas.

"But the time is now.

"Six weeks out (from finals), we have got to find a way to improve and set our game up in the best way possible to win at the right time of year.

"We know that footy is a rollercoaster. We know there's going to be times in the season where you're not quite at your best.

"But the thing that sits right before us as a footy club is to get ourselves going.

"We get an opportunity to get back to playing our best footy and set us up in the best way."

The Demons won their opening 10 matches in style, including a round four hammering of Port in Adelaide.

In that encounter, the Power didn't score a goal until 22 minutes into the third term - and only mustered four in the entire match when beaten by 32 points.

That defeat was part of five winless games for the Power to start their season - they have since won eight and lost three.

"They're a completely different side (now), they're playing a completely different style to earlier in the year," Goodwin said of Port.

"They're playing a really fast style of footy and exciting brand of footy.

"They're going to test us in a whole range of different areas."

History justifies Goodwin's wariness of Port, who will be without coach Ken Hinkley on Sunday after he tested positive to COVID-19.

The Power have won all three games against Melbourne in Alice Springs, though the clubs haven't met there since 2016.