Sydney coach John Longmire thought defender Lewis Melican touched the reviewed Liam Shiels' goal that helped seal Hawthorn's six-point win at the MCG, saying the AFL had to invest in better quality cameras to ensure more accurate score reviews.

With the scores level at the 13-minute mark of the final quarter, Hawthorn midfielder Shiels scrambled between Melican and fellow Swans defender Dane Rampe to soccer the ball through on the goal-line.

The goal umpire indicated he thought Shiels had kicked a goal but called for a review to see whether Melican, who made a desperate lunge, had punched the ball through.

The available vision was inconclusive, so the umpire's original call stood, putting the Hawks six points up. From there, they were never headed.

Longmire told reporters after the game he initially thought Melican had punched the ball over the line, but added a disclaimer: "Clearly I'm sitting on the red and white side of the fence, so I'm going to have that view."

The Swans coach said he supported the principle of score reviews but stressed the quality of the vision being used was undermining the system's credibility.

"I really like the concept of the goal review, but unless we get better cameras it

almost defeats the purpose of it," Longmire said.

"I really like the idea that you try and get the right score, that's what it's all about. But surely there is better vision that we can achieve.

"There are better cameras or better views that we can get in world sport somewhere, that can actually determine and slow the ball down so it's not as blurry and you can work out what it is.

"We need to spend some money, I don't know I'm not up there with the technical camerawork, but hopefully we can actually invest and get some quality cameras that can actually determine what's actually happened, rather than just seeing the blurred vision we see now."

The Swans' loss broke a streak of seven straight wins and will see them slide from sixth on the ladder to seventh if Melbourne defeats North Melbourne at Blundstone Arena on Saturday.

Their disappointment was compounded by injuries to captain Josh Kennedy (left hamstring) and ruckmen Sam Naismith (knee) and Callum Sinclair (ankle) during Friday night's game, while Jake Lloyd (hip) and Gary Rohan (back) were late withdrawals before the match.

Kennedy and, to a larger extent, Naismith spent extended periods on the bench during the second half, but returned to the field with strapping, while Sinclair hobbled from the ground late in the match.

Longmire was unsure how serious their injuries were.

"I'm not sure what they are like at the moment, but there are a few pretty sore. (We'll) have to see how they pull up," he said.

Longmire said Kennedy had experienced hamstring tightness in the third term.