Darcy Byrne-Jones re-signs with the Power until the end of 2018.
"Playing my first AFL game earlier in the year was a dream come true and it's been a thrill getting the chance to go out and play all season," Byrne-Jones said.
"I've learned a lot from my coaches and senior teammates down back, and I've still got plenty more to do."
Power coach Ken Hinkley said Byrne-Jones had deserved his chance to nail down a spot in the senior side.
"You know what a player like Darcy is going to give you every time, when he crosses that line he gives you 100 per cent," Hinkley said.
"I don't think anyone would say 'Darce' hasnít earned his place in our team this year, but that comes from two years of really strong, hard work in the SANFL and during pre-season.
"He's only played his first year of AFL footy, but he handles himself well out there and we've been really comfortable with giving him some important jobs to do."