PORT Adelaide star Robbie Gray has been cleared to face Greater Western Sydney at Adelaide Oval on Sunday after overcoming concussion.

The Power will also unveil its first debutant this season with mature-age recruit Jarrod Lienert coming into the side, while running defender Jasper Pittard is recalled in place of Riley Bonner.

Gray's inclusion is a huge boost for the fifth-placed Power as they aim to bounce back from last Sunday's disappointing nine-point loss to Fremantle at Optus Stadium.

Gray was knocked out as a result of Ryan Nyhuis's sling tackle that earned the Dockers player a three-game suspension for rough conduct.

"He's right to go, which is really positive, because we all saw the incident," Power coach Ken Hinkley told reporters on Friday.

"As we said straight after the game, Rob was pretty positive about how he was feeling, and he's now done his concussion testing and passed all of those, and as you saw today, he was running around today.

"He ran around on Wednesday as well, so he's been pretty positive all through the week.

"We've still got to get to Sunday, and we'll make sure he's OK tomorrow.

"In any of these circumstances with concussion, you're never quite sure when it may come up again."

Lienert - who was sidelined for two months after knee surgery in May – gets his opportunity after impressive SANFL form in recent weeks.

At 193cm and 89kg, the 23-year-old defender has the size to play on key forwards, but also the pace to play on quicker opponents.

It's his second year on the Power's rookie list having been a part of Sturt's premiership-winning team in 2016.

"He probably would've played well before this (if not for the knee surgery) and he's worked his way back and he's playing some really strong football," Hinkley said.

"He's been playing as a key back, he's got a bit of pace, he's got a nice leg, some really positive things.

"He's got some AFL stuff that will make us better."

The Power are without defender Tom Jonas for the next month with a knee injury.

Charlie Dixon and Justin Westhoff will share the ruck duties in the absence of the injured Paddy Ryder (hip flexor).

It was the same combination the Power went with earlier in the season when Ryder missed five games with an Achilles injury.

"We've had experience in it this year, so it's OK," Hinkley said.

"We know what it means, it means some slight disruptions in a perfect world you wouldn't want to do, but it's round 18 coming up, there's injuries all over the AFL, we're no different, we've got some injuries.

"Clearly, we'll be a bit smaller (in the forward line) because of that reason, but we've got some flexibility in that space with plenty of midfielders that can go forward."

Power vice-captain Ollie Wines was restricted to shuttle runs away from the main group on Friday, but isn't in any doubt for Sunday's game.

Hinkley expected Ryder to resume running early next week.