SYDNEY Swans coach Paul Roos says Saturday night's game against Collingwood at ANZ Stadium is the club's biggest for a number of years.

With the Swans at 5-6 after 11 rounds, a loss against the in-form Magpies will leave the club falling behind its rivals for a top eight berth.

The corresponding fixture in recent seasons has signalled a decline for the Swans but Roos said his players were aiming for a different result.

"The Collingwood game over a couple of years – certainly last year – has led to us having a poor second half. Hopefully we can kickstart our second half this year," he said on Friday.

"It's a big game, it's a huge game for the club. It's always a great fixture against Collingwood, regardless of where we are on the ladder but certainly with both teams at 5-6 and 6-5, it's a massive, massive game for us."

Versatile tall Heath Grundy would play in defence on Saturday night as forecast earlier in the week, to cover the absence of key defender Craig Bolton.

Roos said the resulting positional shuffle could help the Swans in their bid to break a six-game losing streak against Collingwood that stretches back to round 13, 2005.

"Obviously you don't like to miss your better players, clearly, but that's just the reality of the team we put on the field tomorrow. We'll give someone else a chance," he said.

"We have to do something different against Collingwood anyway, because we haven't done that well against them the last five or six times. Obviously it hurts us a bit but hopefully we can cover that and play just a little bit differently.

"We'll do slightly different things against them and hope that it works but the bottom line is tactics can sometimes be overrated. It's really about who wants it more."

Roos said Rhyce Shaw's inside information on the Magpies' tactics had been handy but he said it would have limited impact on the result.

"We all know roughly how everyone plays, but it's more just that intimate knowledge that we don't get," he said.

"We don't know what Mick tells them, we don't know how [Alan] Didak is told to play specifically or [Rhyce's] brother Heath, so it helps but it certainly doesn't guarantee anything."

Youngster Nick Smith and Kristin Thornton join Ed Barlow as inclusions for the clash and Roos said the experience would be vital for the pair.

"There's no doubt that one of the reasons we were able to win a premiership is because we started these blockbusters… we did okay and we lost a couple and we made a grand final in 2005.

"If we hadn't have had the blockbuster games against Collingwood, it's debatable as to whether we would have been able to get to where we got to in '05.

"It's the start for these guys. It's a big crowd, it's a good atmosphere, the opposition's fantastic so win, lose or draw, it's going to be a great experience for those young guys."