Fremantle have revealed veteran Nat Fyfe is facing up to a month on the sidelines after hurting his calf in a warm-up on Sunday.

Named as the tactical sub for the home game against St Kilda, Fyfe went unused by the end of the two-goal win, raising eyebrows over his no-show.

Coach Justin Longmuir revealed post-game that Fyfe had hurt his calf while warming up at half-time of the match, forcing the Dockers to keep the two-time Brownlow Medal winner out of action.

Scans have since revealed a moderate calf strain that will sideline Fyfe for 2-4 weeks in what is the latest frustrating injury blow for the midfielder.

โ€œObviously frustrating for Nat after he was able to get some continuity with his body in the last monthโ€ said Fremantle Executive General Manager of Football Joe Brierty.

โ€œHe will now commence an offloading and reconditioning period and our performance health team will set the program with Nat to return to football in the next few weeks.โ€

The player needing a BIG pre-season at your AFL club
Nat Fyfe during the 2022 AFL Round 19 match between Richmond and Fremantle (Photo by Cameron Grimes / Zero Digital Media)

Fyfe has played just four games this year, all as either the starting sub or being subbed out.

The 33-year-old underwent knee surgery prior to the season and faced a further setback in April when he strained his hamstring playing in the WAFL.

The Dockers champion managed 22 games under Longmuir last year, but failed to play 10 or more games in the two prior campaigns.

Fremantle currently have Alex Pearce (shin), Will Brodie (concussion), Cooper Simpson (shoulder), Sam Sturt (knee), Hayden Young (hamstring) and Sam Switkowski (hamstring) sidelined through injury.

The Perth side face Sydney in New South Wales on Sunday, with Fyfe forcing the Dockers into at least one change for the Round 17 clash.