PORT Adelaide key defender Tom Clurey has signed a two-year contract extension with the Power until the end of 2019.

The 23-year-old has played 32 AFL games, including 18 in a row since round 15, 2016.

Clurey – the 29th overall pick in the 2012 draft – has cemented his spot in the side after just nine games in his first three seasons.

"The first few years were a little bit difficult, but I knew I had to get that consistency in my game and there were plenty of things I had to work on," he told reporters on Wednesday.

"I knew if I kept improving each year and kept working hard throughout the pre-seasons, and when I did get an opportunity, I would make it stick.

"It's good it's finally paid off."

Clurey has been given the responsibility of taking some of the premier key forwards in the competition.

He lined up on Sydney star Lance Franklin in round one, and last weekend stood Richmond spearhead Jack Riewoldt.

"There are plenty of good forwards and I don't mind having a target to try and beat," Clurey said.

"Every week, no matter who you're playing on, you want to do your job and beat them.

"They're big, strong players and if you're not physical and you can't compete in the contest, that's when they're going to get the edge on you.

"Over the last couple of years, I've tried to increase my strength in the gym and that's holding me in good stead."

Clurey is the fifth Power player to re-sign in the past two weeks.

He follows key defender Jack Hombsch and promising ruckman Billy Frampton signing until the end of 2019, and midfielder Brad Ebert and NAB Rising Star contender Sam Powell-Pepper extending their deals until the end of 2020.

The Power held off negotiations with all players until they returned from their historic game in China against Gold Coast in round eight.

It coincided with the collective bargaining agreement between the AFL and the AFL Players' Association being finalised to have certainty in the salary cap.

Free agents Jackson Trengove and Jasper Pittard headline the list of 15 players who are uncontracted next year.

Others are veteran utility Justin Westhoff – who coach Ken Hinkley says will definitely be at the club in 2018 - Karl Amon, Matthew White, Sam Gray, Aaron Young, Aidyn Johnson, Angus Monfries, Brendon Ah Chee, Dougal Howard, Riley Bonner, Jesse Palmer, Logan Austin and Nathan Krakouer.

On top of that, the Power will be keen to retain rookie-listed defender Dan Houston after breaking into the side this year.

Trengove, Pittard, Westhoff, White, Gray and Houston all played in the Power's 13-point loss to Richmond last weekend.

Amon has played eight games this season, but is currently sidelined with a knee injury.

More on portadelaidefc.com.au...