MASON Cox is helping to get the best out of Fremantle superstar Luke Jackson and has done enough to keep Sean Darcy out of the Dockers' side, according to All-Australian Kate McCarthy.

Walyalup is flying having won eight games on the bounce and Jackson has been arguably the best player in the League in the past month, including a best-on-ground performance against Hawthorn on Thursday night.

Jackson's recent purple patch has coincided with Cox coming into the side in place of Darcy, who has been sidelined by concussion and then a calf issue.

In four games with Cox in the side instead of Darcy, the percentage of ruck contests Jackson has taken each game has risen to an average of 71 per cent compared an average of 45 per cent when Darcy was in the side to start the season.

Darcy is set to miss at least another three weeks due to his latest injury, but McCarthy believes the Dockers should stick with the status quo, even when Darcy is available again, given Jackson's hot form.

"I struggle to see him making his way back into this team straight away," McCarthy said of Darcy on The Round So Far.

"I like what Mason Cox is offering ... (which is) the ability for Luke Jackson to play as many minutes as possible in the ruck and then rest forward.

"The percentage (in the ruck) that Luke Jackson is getting to play, I don't see how he was getting the best out of himself when Darcy was in the team. And for me, when we see the best of Luke Jackson verses the best of Sean Darcy, we get more out of Luke Jackson.

"It's a very tough decision to be made, but I'm keeping the ruck combination that they've got."

Not only has the selection of Cox seemingly brought the best out of Jackson, the American has been a solid contributor himself, averaging 7.2 disposals and three marks per game since earning his club debut against the Eagles in round six.

After the pulsating win over the Hawks, Dockers coach Justin Longmuir said it was Cox’s work in the ruck early in the fourth quarter that helped tilt the game in his side’s favour.

"I thought actually Cox gave us something in the ruck early in the last quarter, which gave us field position,” he said. "And Jacko being forward actually probably straightened us up a little bit and got us deep entries," he said

Ruck contest percentage, Fremantle, 2026

*Darcy was removed from the game in the second quarter due to concussion