ROBBIE Gray has withdrawn from the Port Adelaide side to face Hawthorn in a blow for the Power's bid to beat the Hawks for a second successive time at Adelaide Oval on Saturday night.

A calf injury forced Gray out of the side on Friday morning. He will be replaced in the selected side by Brendan Ah Chee, who had been omitted from the Power side that defeated North Melbourne in round three.

Gray corked his calf in last week's win over North Melbourne and although the club was hopeful he would be fit to face Hawthorn, the Power decided on a conservative approach, making the change after coach Ken Hinkley's press conference on Friday morning.

It is not known whether Gray will be forced to miss more than one week.

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Meanwhile, Port Adelaide will look to rotate ruckmen Paddy Ryder and Matthew Lobbe through the forward line on Saturday night at Adelaide Oval.

The pair is yet to play together, with key recruit Ryder ruled out of the NAB Challenge as he awaited the verdict in former club Essendon's anti-doping hearing, before Lobbe injured his quad on the eve of round one.

Lobbe has missed the opening three games of the season with the injury but his inclusion this week will finally allow coach Ken Hinkley the opportunity to play his two big men in the same side.

Ryder has been forced to assume the bulk of the club's ruck duties in Lobbe's absence but Hinkley said the former Bomber would be used more as an attacking threat now that his ruck partner was available.

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"That's exactly what we hope, or for 'Lobes' to spend time in the forward line, which then puts significant pressure on opposition defences because they are those big bodies that you can actually kick to under a bit of pressure," Hinkley said.

"We're a bit like everyone, we're trialling it a little bit and seeing what it's going to look like because we haven't had the chance.

"There was interruptions in the pre-season with Paddy and then we get to the start where we think we've got them both and then 'Lobes' gets the injury.

"We're about to find out [how well they work together]."

Lobbe's inclusion also helps to ease the loss of inside midfielder Ollie Wines who dislocated his wrist last weekend and will miss up to six weeks.

Hinkley said the ruckman's "elite" stoppage pressure – he led the Power for tackles last season – allowed fellow mids such as skipper Travis Boak and Brad Ebert to concentrate more on their offensive games in congested situations.

"We know how important 'Lobes' is to us but we weren’t going to take the risk because of it being a long season; we just had to make sure with the thigh that we got him right," he said.

"His follow-up pressure at ground level is elite and he clears a path for some of those boys.

"[Inside pressure] has been there at times but it hasn't been consistent."

More to come