Gray was knocked out last Sunday in Port's loss to Fremantle but has passed concussion tests.

Gray was felled in a Ryan Nyhuis tackle which resulted in a three-game suspension to the Docker.

"He is right to go which is really positive," Power coach Ken Hinkley told reporters on Friday.

"Rob, as we said straight after the game, was pretty positive about how he was feeling and he has now done his concussion testing and passed all those."

Hinkley said Port would make two changes for the Adelaide Oval fixture against the Giants, with ruckman Paddy Ryder unavailable because of a hip injury and halfback Riley Bonner dropped.

Jasper Pittard will replace Bonner while the Power will also debut Jarrod Lienert, a 23-year-old key defender.

"He (Lienert) has been playing really well (in the state league)," Hinkley said.

"He had an interruption when he had some knee surgery, he probably would have played well before, this to be fair.

"And he has worked his way back, three weeks now, and he has been playing some really strong football.

"He has got pace, he has got a nice leg, he has got some really positive things ... we think he has got some stuff which will make us better."

Australian Associated Press