PORT Adelaide key defender Jack Hombsch has signed a contract extension, securing his playing future at Alberton until the end of 2017.

Hombsch was contracted to the end of 2015, but Port announced on Wednesday that the defender had re-signed for another two years.

The 21-year-old enjoyed the best season of his short career in 2014, missing just one game as the Power progressed through to a preliminary final.

Port coach Ken Hinkley said Hombsch had taken his game to a new level in the past year.

"Jack's form really reflects that of the team, he's worked really hard on his game and his confidence has grown from there," Hinkley said.

"He can play on talls or mid-size forwards and become an integral part of our backline structure."

Hombsch follows teammates Robbie Gray and Matthew Lobbe in penning new deals in recent months. 

He played six games for Port in 2013, his first year at the club after crossing from Greater Western Sydney in a deal that also landed the Power small forward Jake Neade.