KEN HINKLEY is confident Port Adelaide's forward line can handle being without Justin Westhoff at times against Essendon on Saturday night, when the versatile big man is required in the ruck.

Jackson Trengove’s work as the Power's second ruckman this season has allowed Westhoff to roam the forward line, relieved of his backup ruck duties.

But with Trengove set to miss up to six weeks after undergoing ankle surgery this week, Hinkley said Westhoff would again be pushed into the ruck against the Bombers.

Although describing the change in plan as a "disruption", the Power coach said it was a familiar move and tipped his attack to fire regardless.

"The biggest disruption is the 'Jacko' (Trengove) in the ruck. Obviously we can't replace him, so we have to go down the other end and look to Westhoff more often than not," Hinkley said.

"We're talking small moments in the game, we're not talking for big parts of the game.

"We've taken Westhoff away from (attack) and put him behind the ball at times (this year) too…so we think our forward line functions pretty well when its small or a bit taller."

Hinkley also defended his decision to avoid replacing injured key defenders Alipate Carlile and Trengove with like-for-like players.

It was expected the pair would be replaced by fellow defenders Cam O'Shea (193cm) and Tom Clurey (191cm).

O'Shea was named but Clurey was selected only as an emergency.

Hinkley said the loss of a tall defender wouldn't disturb the club's back-half structure, claiming it was always the plan to select just one tall defender.

He talked up 20-year-old Clurey's form and development but said it was O'Shea's previous experience (48 games) that edged him into the team.

"It was either going to be Tom or Cam O'Shea…Cam's got a little bit more history of playing AFL football," he said.

"Typically we've had one extra down there (in defence) most of the time, so one of our talls have had to play small.

"It doesn't disrupt us that much."

A win is crucial for Port on Saturday night if it's to remain in the top two, with the Sydney Swans, Fremantle and Geelong all threatening to overtake.

Despite the importance of the match and in the wake of the side's loss to Adelaide last weekend, Hinkley said he hadn't noticed a lift in Port's training intensity.

He was quick to point out the value of a stable mentality.

"You don't really want it to change because you want the mindset to stay the same all the way through – that's what gives you consistency in performance," he said.

"We train to win and that's what the boys want to do."