Fremantle ruckman Sean Darcy will be used sparingly whenever he and Luke Jackson are in the same team as part of a plan to protect his body and maximise the impact the team has at stoppages, coach Justin Longmuir has revealed.

Darcy will come back into the team after being rested against Essendon last week, so Fremantle will have two ruckmen to take on St Kilda at Optus Stadium on Sunday. Jackson was best on ground against the Bombers.

There has been a huge focus on Fremantle’s ruck division, with many experts believing Jackson and Darcy can’t play together. But Longmuir insists they give the team added strength.

He said Fremantle would look to use Darcy for shorter periods of the game, just as they did when he spent 50 per cent of the match on the field against Gold Coast and then had 61 per cent game time against North Melbourne.

“While Sean is building form, he’s happy to play whatever role the team asks of him. He cops a little bit of lower game time, but that’s probably going to be the new way for him in some respects,” Longmuir said.

“It’s probably more about his body than anything. He’s been injured a lot. When we’ve played him, we’ve played at 90-95 per cent in the ruck, which is a demanding position. We need to make sure we look after him and his availability as much as Jacko.”

Longmuir isn’t wedded to any plan for how Jackson and Darcy will be used each week, saying it is important to read each game. But he said Jackson was enjoying the opportunity to play as a forward or midfielder when Darcy is in the ruck.

He said form would dictate the team’s tactics.

“The set plan doesn’t really change and hasn’t changed since we’ve had them both in the team. Whoever is going better against a certain ruck at a certain time might get a bit more ruck time as the game unfolds,” he said.

“If we feel like Luke is doing a good job in the midfield or forward, we’d leave him there. We feel like it gives us plenty of levers to pull. Every week is going to look slightly different.”

While Darcy will come back into the team, veteran Michael Walters has suffered another setback after pulling up sore from his WAFL game last weekend.

Walters won’t play for Peel, but Longmuir is hoping he will only miss one game.

There is plenty of competition for spots in the forward line and Isaiah Dudley will come back into the Fremantle team for the first time since the Dockers beat Port Adelaide on May 24.

“He didn’t get dropped. He went out of the team for personal reasons and was away from the club for a bit over two weeks,” Longmuir said.

“We thought it was best for him and best for the team to work his way in with a couple of games at Peel. He’ll come back into the team this week. His form has been good at Peel.”