SYDNEY COACH Paul Roos is adamant "you have to do everything right" to defeat Geelong on its home turf.

The 2005 premiership coach should know, as his side took it right up to the Cats at Skilled Stadium on Saturday before Geelong booted five unanswered goals in time-on during the final term, running out 42-point winners.

"With their ability to rotate so many key midfielders through and with [Tadhg] Kennelly out as well coming into today - you lose another quality player - and they've got a lot of quality players. You've got to do absolutely everything right to be able to beat the team at Kardinia Park," Roos said.

"For probably three-and-a-half quarters, we did most things really, really well, but they're a very, very good side."

Roos praised the performance of Geelong dynamo Gary Ablett, who was best-on-ground with 35 disposals and three final-quarter goals against the Swans.

"When you're biting, battling, scratching, fighting - that's where your class rises to the top. All of a sudden, you get a couple of Gary Ablett goals that clinch the game," Roos said.

"Once the floodgates opened, our guys were pretty buggered at the end and it was able to open up. But (Ablett) was just phenomenal today."

While quick to praise Ablett's influence, Roos admitted he was disappointed in the performance of dual Brownlow Medallist Adam Goodes, who had 14 touches opposed to Cameron Ling.

"'Goodesy' has struggled again today, and that's a massive concern. You get 35 [disposals] and three goals from Gary Ablett, and probably our key player, our best player, has a really bad day," Roos said.

"It's frustrating as a coach because you've got to move him around to try to get him in the game, and sometimes it unsettles the coaching staff a little bit because you're trying to get your good player involved.

"Today he probably could have kicked four goals, but even his goal-kicking was astray.

"But you can't spend all your energy on one player."

Roos said the loss of key forward Barry Hall, who was serving the first of a seven-match suspension, didn't have a major impact on the loss.

"I wouldn't have thought (so), looking at the game today," Roos said.

"We took them to (three) points in the middle of the last quarter, and we looked like a team that came to compete and competed for most of the game. In the end, we got beaten by a better team.

"I think our ball-use probably wasn't great. When we used it well, we actually played really, really well. 'Hally' is obviously a good player, but I don't think that was the major issue today."