Fremantle's injury woes have gone from bad to worse, with exciting youngster Minairo Frederick suffering a calf strain.

As first reported by The West Australian's Jordan McArdle, the injury is expected to sideline the 20-year old for three weeks.

Frederick is coming off an impressive two-goal display in Sunday's AAMI Community Series clash against West Coast and is set for more senior opportunities this year.

He was drafted with Pick 61 in the 2019 AFL draft and made his debut last year, playing 10 games for the club.

Frederick joins Michael Walters (hamstring) Rory Lobb (knee), Bailey Banfield (syndesmosis) and Mitch Crowden (calf) on the sidelines, who will all be out for extended periods.

The Dockers are set to get their 2021 season underway against the Demons at the MCG on Saturday, March 20.