FREMANTLE coach Justin Longmuir will miss another game after a change in his COVID-19 status extended his time in the AFL's health and safety protocols.

Longmuir watched from isolation as the Dockers won Sunday's Western Derby by 55 points, with assistant coach Jaymie Graham stepping in to take the reins.

Fremantle football manager Peter Bell confirmed Graham will again lead the side in Saturday's round four game against Greater Western Sydney following the update to Longmuir's status.

"We were really pleased with the way our coaching team, players and staff quickly adjusted and then planned, prepared and collaborated to get the desired result on Sunday," Bell said.

"Justin was able to communicate with the coaching team throughout the game and we will look to operate in a similar way on Saturday against GWS."

Longmuir, who initially entered protocols on Thursday afternoon, didn’t speak directly to Graham during the Derby but was able to contribute from afar.

"I didn’t get to talk to him personally," Graham said after Sunday's game. "He did have a feed to the box and he gave us his feedback and what he was seeing. 

"He got to see a little bit himself, we were in the heat of the moment. It was good to get his views and opinions."

Former Eagles assistant Graham became the first-ever coach to lead both West Coast and Fremantle, having stepped in during the 2018 season when Adam Simpson was absent for personal reasons.

Meanwhile, Darcy Tucker was back on the track and walking laps away from the main group on Tuesday morning after a scary incident in the third term of the Derby where he collapsed following a tackle.

David Mundy was also sighted undertaking light duties after missing the past two games due to the AFL health and safety protocols.