PORT Adelaide coach Ken Hinkley has claimed the score review system is forcing umpires to second guess their own judgement after a crucial call went against the Power in their one-point loss to Greater Western Sydney at Adelaide Oval on Saturday.

Power defender Tom Clurey had taken possession of the ball close to his goal-line and had handpassed to a teammate when the goal umpire signalled the ball had gone over the line for a behind.

The decision was then sent upstairs and the score review concluded the ball was in play and the ball was thrown up at the top of the goalsquare, despite the Power being in possession of the ball when the review was made.

Robbie Gray and Justin Westhoff leave Adelaide Oval disappointed after the narrow loss. Picture: AFL Photos

To rub salt into the wound, Giants forward Jeremy Cameron kicked a goal from the subsequent stoppage, six points that would prove vital in the final wash-up as the visitors got home 8.8 (56) to 7.13 (55) in a low-scoring scrap.

"I saw the umpire in the absolute perfect position and I go, why haven't you called that?" Hinkley said.

"Does the score review now frighten the umpires to the point where they're not prepared to make the call and back their call?

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"Whether it works for you or works against you, you almost can't win.

"It's just disappointing because the very next stoppage, they kick a goal.

"From what I've seen, I'm sure the umpire's in a really great position and did a really great job, I just wish he'd perhaps not called a maybe point."

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Hinkley confirmed the umpire made the correct call to award a ball-up after the score review decision was made but was frustrated they had to go to the score review in the first place.

The Power trailed for the entire game but had a couple of chances late in the fourth quarter to snatch what would have been a vital victory.

"Disappointing result, but you couldn't question the way the boys went about it and the way they stuck at it," Hinkley said.

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"I felt there was one team at the end trying to win, and one team out there trying to defend, and we were trying to win near the end.

"We have to win, we clearly get that at this stage of the season, we have to look for as many as we can possibly get to give ourselves (a chance) to be a part of it later in the year.

"We still sit here tonight almost in the same position as before tonight, and what a difference four points may have made, but we didn't get them."

The Power (8-10) remain one game outside the top eight ahead of next Saturday's encounter with Essendon at Marvel Stadium.