Channel Seven AFL expert Kane Cornes has warned Fremantle about tinkering with their ruck set up ahead of the pending return of Sean Darcy, with concerns his inclusion could hurt star Luke Jackson’s “unreal form”.

It comes as the former Port Adelaide midfielder also heaped praise on Dockers vice-captain Andy Brayshaw, who was one of the stars who drove the side to victory against fellow premiership contenders Geelong on Thursday night.

Justin Longmuir’s outfit recorded a remarkable 13th consecutive win when they defied their own wayward kicking in front of goal to beat the Cats by nine points at Optus Stadium.

Jackson is almost certain to poll maximum Brownlow Medal votes for the clash after he racked up 28 touches, three goals, nine tackles, 25 hit-outs and six clearances in a monster performance.

But while Jackson’s form is proving to be instrumental in their push for a maiden premiership, the Dockers still have questions around who partners the 24-year-old in the back half of the season.

Doig medallist Sean Darcy is still in the WAFL as he builds fitness from his latest injury setback, while high-profile recruit Mason Cox has not done enough to secure his spot in the best 23 in the former’s absence.

Cornes said Longmuir and the Dockers could not afford to cut Jackson’s time in the ruck should they choose to pick Darcy ahead of Cox in the coming weeks.

“The last thing that you want is to disrupt the momentum that you’ve got … he (Jackson) is the best ruckman in the game right now. He’s not the best forward, the best mid, the best wingman he’s the best ruckman so the last thing you want is his ruck contests to diminish like it has when Darcy has been there,” Cornes told AFL.com.au.

“You’ve also got the fact that they’re going to have to rest him throughout the time and once they secure top two you just want to take a few miles off him but when it comes finals time you want this guy to be rucking for 80 per cent of the games which makes it hard for Sean Darcy.

“They’ve been patient with Sean and want to get him fit through the WAFL, but Mason Cox wasn’t great, so we’ll watch that and how it develops and how it possibly affects Luke Jackson’s unreal form in the next month or so.”

Cornes said Darcy would have to improve his forward craft if he was going to play ahead of Cox.

“If he plays, he has to be prepared to play and compete and if that’s competing as a forward he has to do it better than what he has done when he hasn’t been probably physically fit enough to do it,” he said.

“It’s a good problem to have but it’s a tricky one on how Justin Longmuir is going to handle this.”

While Jackson is sure to be rewarded for best-on-ground, Cornes praised midfielder Brayshaw who had an incredible 16 touches in the third term when the Dockers made their move to beat the Cats.

Cornes said Brayshaw was “the difference in crunch time” as part of a star-studded midfield that featured the return of Caleb Serong. “I was a bit worried about him at the start of the year, he just seemed to be pushed out of the midfield for a little bit, (Shai) Bolton was coming, (Murphy) Reid was coming and he got shoved out,” he said.

“I think he’s sort of allayed those fears. This was the player that I thought lifted the most when the game was genuinely in the balance at half-time.

“He’s not super polished by foot, he’s not going to carve you up like Murphy Reid or Hayden Young, but I thought his defensive action, his smart decision making, his tackling, (he) really was the player who got it going and was the difference in crunch time for the Dockers.”