PORT Adelaide defender Jarman Impey has signed a three-year contract extension that will tie him to the Power until at least the end of 2018. 

The 19-year-old joins star teammates Travis Boak and Robbie Gray and former Brisbane Lion Jared Polec, who have all recently committed to the club for the next three seasons.

Impey, who was recruited with pick No.21 in the 2013 NAB AFL Draft, has played 22 games since making his debut in round one last season. 

"I’m really enjoying my time at Port Adelaide, everyone here has made me and my family feel part of the club from day one," Impey said in a statement on Tuesday night. 

"I’m very excited to be at Alberton and I’m just going to keep working hard to improve my game and do whatever I can to help the club." 

Power coach Ken Hinkley praised Impey’s work ethic and said he had applied himself to everything he did since joining the club.

"He wants to learn and grow as a player to make this team better and that’s all you can ask as a coach," Hinkley said.

Impey, who been assigned to the opposition's most dangerous small forwards this season, recently returned from a four-week hamstring injury.