ADAM Goodes faces the highly unusual prospect of a scan on a soft tissue injury after the dual Brownlow medallist was forced off the ground in the final quarter of the Swans' loss to Adelaide on Saturday night.

One of the most durable players in AFL history, Goodes has played a minimum of 20 games in each of his 13 seasons in the League.

But that streak could be in some jeopardy after he sustained what coach John Longmire called "either a hip flexor or a high quad injury" six minutes into the final term of the 15.9 (99) to 14.10 (94) loss - a defeat that ended the Swans' unbeaten start to the season.

"We don't know yet," Longmire said after the game.

"We'll need to get a scan to find out exactly what it is. I don't know to be honest and I don't think he knows.

"He hasn't had too many soft tissue (injuries), so he probably doesn't know himself. We'll have to see what the scans say but if you asked him, he probably wouldn't know much either.

"He was probably scratching his head wondering what it was."

Goodes, who had kicked five goals in another outstanding display in his 305th game, was charging out of the goalsquare, aiming to take another mark, when he pulled up and immediately grabbed high on the back of his left leg.

He tried to run it off, but within minutes was subbed out of the game for Andrejs Everitt.

"I thought it might've been his hamstring to be honest, but I didn't quite know," Longmire said.

"Then the doc had a chat to him and I suspected it was something bad enough for him to come off the ground.

"He played an important role for us and obviously I'm hoping he's right next week, but not sure at the moment."

There was an extremely sombre mood in the Swans dressing room after the game as they dealt with their first defeat from six matches in 2012.

Longmire pinpointed the two areas where he felt the game was lost.

"It was probably the first quarter," he said, which ended with Adelaide holding a 24-point lead.

"We didn't capitalise on our forward entries and didn't use the ball very well in that first quarter and the first 10 minutes of the last quarter.

"Ultimately we were seven points up and they came out and kicked the first four goals."

Longmire was also asked about Sam Reid, who had another very quiet night against the Crows.

A week after showing some kicking yips and gathering just five disposals against Hawthorn, Reid was again rarely sighted on Saturday night, finishing with six touches and no goals.

"He's been a bit sore for a couple of weeks with a few niggles and he hasn’t done a lot of training," Longmire said.

"He was able to do a full session on Thursday, his first full session for a couple of weeks, so hopefully now he can get into a full training program and that will help his form.

"You have to be able to train to get your form."