SYDNEY Swans forward Sam Reid is expected back before the finals after suffering a partial medial tear to his right knee on Saturday night.

Reid was taken from the field during the first quarter of the 72-point win over Gold Coast and did not return.

But the post-match diagnosis was good news for the Swans, with coach John Longmire saying he expected the 20-year-old to miss "a couple of weeks".

The news was also positive for dual Brownlow medallist Adam Goodes who suffered a corked thigh late in the match, but is expected to play next week.

For Reid, it seems the best possible outcome after he fell awkwardly in a marking contest and was assisted from the field after 15 minutes.

"At this stage we think it's a partial medial tear," Longmire said.

"He's getting some scans tomorrow (Sunday) to check what it is. The good thing is it hasn't swollen too much, he's walking around on it OK.

"He'll get a scan to make sure that's what it is and if that's the case it's probably a couple of weeks which would in the end be a good result."

Longmire said the Swans' doctor had confirmed the injury was not an ACL.

He said it was only late in the match he had time to consider the fall-out of Reid's absence.

"You just have to try and adapt and look for what's immediately in front of you and you really don’t get into it until the last quarter," he said.

"We had Mummy (injured ruckman Shane Mumford) sitting there and hopefully he'll come back in next week as well which will help the structure."

The Swans did not miss their big man against the Suns, with Lewis Roberts-Thomson's career-best four goals leading the charge of 10 individual goalkickers.

Longmire said he was pleased with the win, particularly the 11 goals to three second half.

"It was a 72-point win which is not easy to do in AFL footy," he said.

"I thought our first half was a bit scrappy. I thought we over-used the ball a bit with hands and it was really slippery. I thought after half-time we adjusted that a bit and started cracking in.

"We adjusted pretty well both to the intensity of the contest and our ball use in the second half, and I thought we hit the scoreboard pretty well."