This season's free agency and trade period has officially closed and so it's time to look ahead to the biggest fish who could be on the market in 2020.

A number of stars will enter free agency who didn't make our list, including, Tom Hawkins, Ben Stratton, Robbie Gray, Bachar Houli, Josh P. Kennedy, Josh J. Kennedy, Shannon Hurn and Easton Wood.

However, due to age or just the sheer unlikelihood that they would leave their clubs, we've left them off our list in favour of guys who are either more getable or in their prime.

Here are the top 10 free agents of 2020:

6. Zac Williams (restricted)

Williams is coming off a career-best season, averaging 23.7 disposals, 5.1 marks and 4.2 rebound 50s and was one of the biggest All Australian snubs.

After getting predominately used across half back during his career, Leon Cameron inserted him into the guts at stages in 2019, where he tore games apart.

Most notably, the 25-year old's performance against Collingwood in the preliminary final stands out, racking up 25 disposals, six tackles, 10 clearances and booting a goal from the midfield in the absence of Stephen Coniglio and Toby Greene.

Williams' stocks are rising and he is sure to receive big offers from rival clubs. However, hailing from the town of Narrandera in New South Wales, he would be more inclined to stay at GWS.

MELBOURNE, AUSTRALIA - SEPTEMBER 21: Zac Williams of the Giants celebrates a goal during the 2019 AFL First Preliminary Final match between the Collingwood Magpies and the GWS Giants at the Melbourne Cricket Ground on September 21, 2019 in Melbourne, Australia. (Photo by Michael Willson/AFL Photos via Getty Images)