AFTER going down to Sydney by 17 points in what St Kilda coach Ross Lyon described as a "critical game", the Saints must win all three remaining home-and-away matches to play in the finals.

The news that Melbourne had upset the Western Bulldogs by seven goals made him pause, but Lyon was not willing to say it gave them any margin for error.

"No doubt (we'd have to win three) — 11 and a half is not going to get you in. It was a really critical game tonight," he said.

"I don't think it makes too many St Kilda people happy; it certainly doesn't make me happy or the group happy."

The Swans played a typically disciplined brand of close, tough football, managing to kick free midway through the last term as the Saints appeared to fall away. The Swans' pressure never gave the Saints players an inch to move in.

Lyon said his side did not cope well with the pressure applied by the Swans but added that he thought his players contributed to their own demise.

"I have to bite my tongue a bit and review it on Monday," he said.

"I thought we competed pretty well (but) I thought some of our decision-making and probably discipline at times was poor. They're a good team and they capitalised on it.

"We won the contested ball but I thought they strangled us a bit and they took their opportunities. And then their confidence grew and from there it was tough.

"I think you have got to give some credit to Sydney, I think it was a combination … of pressure and not being predictable when we had the ball at times to where we wanted to go."

Lyon said the side was "about trying to win a premiership but at the minute, the footy we're playing isn't quite going to win one. You don't want to be limping in. We've got some things to improve to become the team we want to be."

Lyon admitted the month of football between round eight and round 11, when the side lost four on the trot, had come back to haunt it.

Lyon's former boss, Sydney coach Paul Roos, said his side still had room for improvement but he was reasonably pleased with the way his side was playing.

"We're working our way up; I think I said during the week was that the first thing we want to try and do was tick off the top eight and the sooner we win enough games to do that, then you start looking further ahead," Roos said.

"But at the moment at 11 wins, we'd still probably need to win two of our last three to make the eight.

"We need to make sure we keep the momentum going and have a good week on the track and come out and play well again next week.

"I would say it's our best win of the year," he said. "We've come up against a team in very good form and pretty much all their players back. They had a real crack, we had a real crack and we were fortunate to be in front at the end."

Sydney plays the Brisbane Lions at the Gabba next Saturday, while St Kilda takes on Fremantle at Telstra Dome the same day.