"Guerra copped a knock to his shoulder in the Port Adelaide game and with the six-day turnaround he hasn't been able to get to the line," Evans told hawthornfc.com.au.

"We'd be hopeful he can get out and do some training next week and see where he is from there. It depends how it settles down."

While the Hawks' lengthy injury list was a concern for Alastair Clarkson early in the year, the coach has been able to recall some experience.

Evans said Michael Osborne – who missed last week with tonsillitis – would return while Travis Tuck should be "bursting" for another crack at AFL football after a sustained stint in the VFL.

Premiership ruckman Robbie Campbell is the other inclusion.

"I think he was probably best on ground for Box Hill last week," Evans said of Campbell.

"He hasn't played too much state-league football over the last few years and [he's] been our No. 1 ruck, so we knew it wasn't going to take him long to find good form."

Campbell's additions means the Hawks have potentially three ruckmen in their line-up, but Evans said each provided a different element.

"(Brent) Renouf has spent a bit of time up forward, so there's some flexibility there for us," he said.

While Hawthorn must win to keep its finals chances alive, the top-of-the-ladder Saints are cruising towards September.

However, they have lost a host of stars for Saturday, with Nick Riewoldt, Lenny Hayes, Leigh Montagna, Brendon Goddard and Steven Baker all sidelined.

Evans said he had seen St Kilda's team and while noting the changes, suggested the Saints could also throw the Hawks a curve-ball.

"They’ve had a very, very consistent run with team selection up until now," he said.

"It [the changes] might throw a few surprises into the mix because we won't really know exactly how they'll line up given what they’ve picked.

"We'd heard the thoughts [about the changes] and I guess betting markets don't get suspended usually for small bits of information, so we'd expected there might be some.

"But we’ll just wait and see what they put out on the park on Saturday."

Hawthorn
B: Murphy, Gilham, Whitecross
HB: Tuck, Schoenmakers, Birchall
C: Bateman, Mitchell, Lewis
HF: Rioli, Franklin, Osborne
F: Renouf, Roughead, Brown
Foll: Taylor, Hodge, Sewell
I/C (from): Campbell, McGlynn, Kennedy, Shiels

In: Campbell, Osborne, Tuck
Out: Guerra (shoulder), Ellis (ankle), Stokes