THE SYDNEY Swans finished second in a number of statistical categories in their 21-point loss to Geelong on Friday night, but only one number interested coach John Longmire – 47.

That was the dismal number of tackles the Swans laid in an uncharacteristically poor defensive performance.

For a side that prides itself on its ferocious attack on the ball and the opposition, and laid 110 tackles in last season's Grand Final victory over Hawthorn, 47 left a nasty taste in Longmire's mouth.

"When you talk about what AFL footy is about and what we're about, it's certainly more than 47 tackles," he lamented post-match.

"What that's an indication of is pretty simple – our defensive pressure wasn't anywhere near good enough.

"You allow a team as good and skilful as Geelong to run around breaking tackles and don't make them stick, they make you pay.

"It's just not us."

Geelong topped the disposals, the marks, the clearances and the inside 50s while laying 54 tackles of its own.

A thrilling 15-goal opening term excited the full house at the SCG, but not the home side's coaching staff.

"It was an eight-goals-to-seven first quarter, which wasn't something that I was enjoying too much," Longmire said.

"I think we had 12 tackles in the first quarter and ended up with 47 tackles for the game.

"That's not how we should be playing our footy."

With the expectation the Swans would lift after quarter-time, they actually got worse, laying a paltry nine tackles in the second term.

They weren't helped by a knee injury to utility Lewis Roberts-Thomson, who had been one of the Swans' busiest players before being forced out of the game in the second quarter.

His initial prognosis offered some rare good news on a poor night for Longmire, although he is still likely set for a stint on the sidelines.

"The doctor thinks it's reasonably stable," Longmire said of Roberts-Thomson's right knee.

"He'll have a scan tomorrow. There may be a bit of joint damage, we're not sure, but the good sign is it seems to be stable.

"There wasn't any swelling afterwards, which is a good sign, but there's obviously something there which will only be picked up by a scan."

Asked for any positives from the night, Longmire had a tough time, eventually coming up with Dan Hannebery's name before harping back to that damning statistic once more.

"I think the way 'Hanners' went about it, he showed that competitive spirit we know he's got," Longmire said.

"Kieren (Jack) and ‘Macca’ (Jarrad McVeigh) at different times played quite well, but I think overall when you look at summarising the game, it's hard to jump away from those 47 tackles."

The Swans have to quickly dust themselves off and regroup ahead of Monday's trip to New Zealand for an Anzac Day clash with St Kilda.