The injuries to Paul Duffield, David Mundy and Michael Barlow are only minor and there is no cause for alarm, Fremantle coach Ross Lyon says.

The trio all left the field with injury concerns during Fremantle’s 18-point NAB Challenge win over Melbourne at Fremantle Oval on Thursday night.

There were grave fears for Duffield as he was assisted from the ground in the last quarter bracing his left arm. The veteran defender went straight to the rooms but Lyon said the injury was to his ribs rather than his collarbone or shoulder.

"I thought Paul Duffield might have injured a wrist or an arm, but it's really just rib and some rib cartilage, so nothing dramatic there," Lyon said in the post-match press conference.

"And David Mundy ... he just sort of rolled his ankle. It was really a no-risk approach.

"In the context of what can happen, we're in reasonable shape."

ROSS LYON Q & A

Mundy had ice applied to his left ankle when he was subbed out in the last quarter and Barlow also had ice on his right ankle after being subbed out at three-quarter time.

Lyon was pleased with aspects of his side's performance but frustrated with the Dockers' overuse of the ball.

The Dockers are trialling three talls in the forward line to help free up Matthew Pavlich and the skipper kicked three goals in the first half. Both he and Taberner looked impressive but Lyon said the structure still had issues to be ironed out.

“At times we looked dangerous," Lyon said. “At times we were slow bringing it to them (Pavlich and Taberner).

“There were opportunities to go to them with equal numbers that we didn't take, so we made that more of a focus in the last quarter.

"It’s a work in progress so you have to give them good ground level support but I think we have that with (Hayden) Ballantyne, (Michael) Walters, (Matt) de Boer, (Chris) Mayne and (Hayden) Crozier.

WATCH - Silky skills from Walters

"It was far from an outstanding performance, but at the end of the day it was the first real hit-out."

Lyon said senior players Nat Fyfe, Aaron Sandilands, Garrick Ibbotson and Ryan Crowley were all in line to return for the Dockers' next NAB Challenge match against the Sydney Swans on March 15.

Lyon was also impressed with Melbourne's performance and heaped praise on the Demons' new signing Heritier Lumumba.

"I thought their senior players were very good," Lyon said.

"Heritier was very good, gave good leadership, and (Daniel) Cross was very good."