Fremantle tall Mason Cox has retained his spot, leaving Sean Darcy "disappointed" with the decision.
Cox had been Luke Jackson's support staff during Darcy's injury absence, but the roles reversed in recent weeks.
The former Pie returned to the senior side as Darcy was managed.
"Mason is going to hold his spot in the team," Dockers coach Justin Longmuir confirmed.
"Spoken to Sean. He's disappointed. But when we managed him last week, we told him there was no guarantees. Mason has come out and played really well. There's not too much in it at the moment. Mason is going to hold his spot.
"Sean's form is not where we need it to be. Mason not only rucked really well, but got his marking around the ground over the weekend.
"They're both playing similar game time when they go out there. It's pretty like-for-like with how we're judging them.
"We're doing a lot of work with Sean behind the scenes to get his mobility going. Clearly he's missed a lot of footy. He's been working through that knee injury he had last pre-season. We're doing work with his footwork and ruck craft.
"It's not necessarily about dominating WAFL. His ruck craft is way too good for that level. It's more about what he can do athletically, and lift his athletic profile."
Longmuir also confirmed Shai Bolton will be managed with a hand issue, with Hayden Young returning from injury.
More to come.
