Anstee has signed for another two Super Rugby Pacific seasons, while home-grown flanker Kane Koteka has penned a new three-year deal.
The pair are set to be joined by Wallabies hooker Folau Fainga'a, who left the Brumbies earlier this week and will soon be officially unveiled as a Force player.
Force duo Angus Wagner and Bo Abra signed two-year contract extensions earlier this week, but Jeremy Thrush, Richard Kahui and Greg Holmes have all retired.
Anstee is a former Australian sevens star, but has established himself as a key member of the Force squad during his two years of Super Rugby.
"They (the Force) were the first club to give me an opportunity to play Super Rugby, so it's great to repay their faith in me and be locked in for another two years," Anstee said.
"We want to be playing finals and ultimately competing for Super Rugby titles.
"Next year we want more wins on the board and find a way to win those tight games. With a new coach and new faces joining the club it will bring a new dynamic and an edge to the group."
Koteka was the first graduate of the Future Force Foundation academy to make a Super appearance.
Since debuting for the Force against the Hurricanes in 2015, Koteka has made 41 appearances and won the club's best and fairest award in 2021.
"As a WA local it means a lot to me to continue to play for the Force in front of my family and friends," Koteka said.
"It was always my goal to represent this club in Super Rugby since I joined the academy when I was 15. To have got to this stage and spent a majority of my career in this environment is massive for me personally."
The Force narrowly missed out on a finals berth this year when the Highlanders secured the losing bonus point in their 31-30 loss to the Melbourne Rebels last week.
Simon Cron will coach the Force next year after Tim Sampson's contract wasn't renewed.
6°C