WESTERN Bulldogs defender Ryan Hargrave believes the absence of Justin Koschitzke from St Kilda's line up this weekend will give his side a better chance of shutting down Nick Riewoldt.

The Saints' skipper has kicked multiple goals against the Bulldogs in their past six matches, including 4.5 in round six this year.

Hargrave said the loss of Koschitzke to suspension meant the Dogs would have more options in restraining the spearhead, who has booted 50 goals this season.

"He's usually a pretty big focal point, and it will allow us to put a bit more of an emphasis on him this week instead of having both of them," Hargrave told afl.com.au this week.

"They'll probably focus a bit more on Riewoldt this week and it will mean we can do that as well.

"He's someone we've got to shut down if we want to win."

However, he said the Dogs were preparing for the unbeaten Saints to have the man power to cover the absence of Koschitzke and key back Zac Dawson, who will also miss after he lost his tribunal case on Tuesday.

"It might have an effect on them, but I don't think it will have a huge influence over the game," he said.

"Koschitzke has had a good game against us the last couple of times we've played each other, so Brian [Lake] is probably happier than anyone he's not playing.

"St Kilda is a pretty good side and should be able to cover a loss pretty well. I don't know if it makes a huge difference because they've definitely got the players that can come in that are still pretty good."

Hargrave said he was expecting to again play his new role of running defender this week rather than man up on one of the Saints' forwards.

"I played at half back last time we played them. I did a fair few rotations and basically just took whoever was playing half forward at the time," he said.

"It will probably be the same this week. I'll end up on a few different opponents, not anyone in particular.

"I've played on [Stephen] Milne a couple of times in previous years, but I'd say Jarrod Harbrow would get someone like him."

Hargrave said he didn't believe the Saints' 16-game winning streak had turned into a mental vulnerability for them, and instead would only make them a tougher side to face.

"You gain a lot of confidence from winning," he said. "Early last year, we didn't lose a game in the first eight rounds and we gained a lot of confidence through that. We were able to take that into the rest of the year.

"I don't see how their streak can be a vulnerability. You're winning games, so you can't really take a negative out of it. They don't have to lose one.

"It's hard to find a vulnerable spot for them at the minute. They're playing really well and their forwards are up and about and dangerous, and their defence is obviously the best in the comp at the moment."