THE ENORMOUS effort required to make the finals after losing the first six games caught up with Sydney in Friday night's semi-final, according to Swans coach John Longmire.

Despite going into the game with wins in 15 of the past 17 games, the Swans did not challenge second-placed Geelong in the cut-throat final. 

Their score of 5.9 (39) was their lowest for 20 years, as they lost by 59 points and were left to ponder what might have been.

Longmire said the only explanation he could offer immediately after the loss was that the Swans simply had an off night when they could least afford to do so.   

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"Our blokes looked a bit buggered tonight, to be honest," Longmire said.

"Some of the efforts were amazing to get off the canvas but even given that, you can't help but be disappointed. We didn't really fire a shot."

The Swans had 25 fewer contested possessions, 110 fewer uncontested possessions and 69 fewer uncontested marks than Geelong in a performance in complete contrast to their effort in the elimination final against Essendon.

Shattered Swans captain Josh Kennedy struggled to find words to match the emotion he was experiencing.

"It's pretty painful. It's going to be a long six months," Kennedy said.

"We did a lot of work to put ourselves in that position but just didn't show up tonight."

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The midfield star's explanation for the performance was pure football speak, free of false rhetoric or empty promises of redemption.

"They were just a bit harder, cleaner and used the ball better. It wasn't a matter of personnel or match-ups," Kennedy said.

Longmire agreed, downplaying the significance of Geelong moving Patrick Dangerfield forward or the last-minute withdrawal of Lance Franklin's nemesis, Tom Lonergan, due to illness.

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He kept the result in perspective, saying whatever could go wrong did. 

Longmire said the team's effort to reach finals after falling so far behind the pack in March and April was mighty.

"Not too many teams have done it but once you do it, you want to keep going," Longmire said.

"I sensed our players still wanted to keep going during the week. I didn't sense any drop-off but we dropped off and we let ourselves down."

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The Swans have now won just two finals (the 2012 Grand Final and 2016 preliminary final) at the MCG in their 11 games at the venue since 2005. 

They could not get a quarter-time lead for the first time since round 19, which put the Cats in a good position as they have not lost after leading at quarter-time this season.

Longmire said it was too early to look at what the list needed to improve, saying such discussions would take place when the dust settled. 

"We need to get better," he said.  

"We tend to take a longer-term view at footy clubs."