PORT Adelaide is setting itself for a crucial month of football as it tries to hang onto its top-four spot, says its director of coaching Shaun Hart.

After losing to the Crows last weekend, Port surrendered top spot for the first time since round seven, with Hawthorn surging to first on the ladder after smashing Gold Coast. The Swans are in third spot, equal on points with the Hawks and Power.

Port has now suffered two losses in its past three games and encounters three bottom-eight sides before facing four top-eight teams in its final five games.

Hart said returning to the winners' circle on Saturday night against Essendon was vital.

"We lost a close game to Sydney, they're a very good team and then we lost on the weekend – so reality says we've lost two out of the last three," Hart said.

"All of a sudden we're right in amongst it … we're not two games clear, we're back with another two teams on top of the ladder.

"This month ahead of us will probably determine, I think, a fair bit of what we look like coming into the latter part of the season and whether or not we're a real chance for a top four spot.”

The task of bouncing back from last Sunday's shock loss to Adelaide was made more difficult this week by losing key defenders Alipate Carlile and Jackson Trengove to injury.

Carlile could miss up to three weeks with a hamstring strain, while – worryingly for his short-term future - Trengove has consulted a specialist after having scans on his ankle.

But Hart said he had full faith in the ability of 20-year-old Tom Clurey, who is set to return to the senior line-up after making his AFL debut in round one.

At 193cm, Clurey has the size to match key forwards but his endurance and skills make him a touch opponent to match up on.

"He definitely adds a real bonus, Tom, because he's a great ball user as well," Hart said.

"He can run and run all day and he can use the ball really well on both sides of his body.

"Certainly [he] doesn't have the experience of the other two guys we lose have got, but that's the nature of the game.

"We've got to get on with the job and make sure we get the job done."