HERO debutant Ryan Nyhuis is expected to remain on Fremantle's rookie list in 2018 after being offered a one-year contract extension. 

The new deal is set to reward the Northern Territory product after a breakthrough finish to his second season in purple. 

From relative obscurity, Nyhuis bobbed up to be the unlikeliest of match-winners in a stunning first game in round 16 against North Melbourne.   

The versatile defender, who had never played in attack before, came in late for ill veteran David Mundy and booted four goals – a club record for a debutant - playing as a defensive forward on Robbie Tarrant. 

Nyhuis, 21, kicked two majors in the final five minutes – including a booming shot on the run from outside 50 – to seal a fairytale four-point victory. 

The 188cm backman ended the AFL season with four games under his belt, before playing a key role in Peel's back-to-back WAFL premiership victory.

After keeping mercurial forward Liam Ryan to just one major in last year's Grand Final triumph, Nyhuis was once again the Subiaco star's kryptonite, holding him goalless in the rematch. 

Nyhuis, who was taken with pick 34 in the 2015 NAB AFL Rookie Draft, could play for Freo from round one next season after changes to list rules under the latest Collective Bargaining Agreement.

Fremantle has secured the majority of its existing list for next season, although uncontracted veteran Nick Suban is still in limbo. 

The Dockers could force Suban to wait until after they conclude their business in the NAB AFL Trade Period before deciding whether to offer him a new deal. 

Fremantle's list management team could be busy up until Thursday's 2pm (AEDT) deadline after being rocked by young gun Lachie Weller's bombshell trade request to Gold Coast.

Negotiations to send homesick Harley Balic to Melbourne are ongoing, however high-flying Hayden Crozier has already joined the Western Bulldogs. 

Freo is working to land WA products Nathan Wilson from the Giants, who have rejected a future second-round pick, and Brandon Matera from the Suns.