SYDNEY SWANS coach Paul Roos expects the West Coast Eagles to be as formidable as ever in their first-round match on Saturday week.

The grand finalists of the past two seasons have built an epic rivalry in recent years, with most of their matches - including the two grand finals - decided by less than a goal.

Roos is expecting the premiers to come out firing in the season opener at Telstra Stadium, despite the absence of suspended midfielder Ben Cousins.

"We can't expect it to be any easier (without Cousins)," Roos said.

"They're a great side with a lot of talent.

"Any time you are playing the Eagles ... you do tend to focus on players like Cousins and Chris Judd, but then you take your eye off the others at your own peril.

"Often it's that collective of the opposition midfield.

"They've beaten us before without a couple of very good midfielders playing."

Roos has a healthy respect for whatever team the Eagles will put on the park for the grand final rematch, singling out Andrew Embley, Michael Braun and Daniel Kerr, along with promising midfielders Adam Selwood and Tyson Stenglein.

"They've been very successful over a long period. It's not as if they've just suddenly got up and won a premiership out of the blue last year," he said.

"They've played in four or five finals series in a row.

"So there is a consistent level of performance. I'm expecting them to play very well in round one, regardless of what's gone on."

He was reluctant to comment on the specifics of Cousins' suspension but said he retained respect for him as a player.

"Ben's got some issues to work through. I just hope that at some point during the season he's back playing and he gets over those issues," he said.

Roos, an outspoken critic of drugs in sport, said the issue had gained a lot of attention over the past month and he had taken the opportunity to remind his players of the dangers.

He said he would be "horrified" if any of his players were found to be taking illicit substances.

He also thought the Swans' club culture helped lower the risks.

"It's probably a bit easier for us as a club because virtually all our players are from interstate," Roos said.

"Our guys are living together ... we help them find (housing), we do cooking classes, we do all these different things.

"Simply because we are an interstate club, we're actually helping them do a lot of things outside football.

"In that regard, we know our players very well. I don't think it precludes anything from happening, but we are very aware of what our players get up to and what they do because we have to be.

"They haven't got their parents here, their schoolmates or anything like that, and they very much rely on the club to provide the whole infrastructure not only for their football life, but outside of football as well."