SAM FISHER and Sean Dempster are no certainty to face Richmond on Friday night with the St Kilda backmen needing to prove their fitness at training this week.

The Saints will get Leigh Montagna back from suspension for the Etihad Stadium clash to provide a midfield boost but Fisher (foot) and Dempster (hamstring) remain in doubt with backline teammate James Gwilt saying the pair needs a strong week to get up for the game.

"I'm not sure yet. We'll see if [Fisher] trains or not," Gwilt told SEN on Tuesday morning.

"I think [Dempster] is close; we'll just have to see if he pulls up well from training. I'm not sure.

"It will be in the next week or two, I would think."

With the two defenders out and Tom Simpkin a late withdrawal, Gwilt and veteran backman Jason Blake had to stand tall against Gold Coast on Saturday night.

While the Saints lost the game by 13 points, the two defenders performed admirably in an undermanned backline.

"We were probably trying to take on more responsibility with those guys out because they've got so much experience and leadership as well," Gwilt said.

"Obviously me and Jason Blake were the more experienced ones down there on the weekend but hopefully we look forward to them coming back in the next couple of weeks.

"It will bolster our defence even more."

Gwilt said the Saints were too "bomby" in their delivery into the forward line, which hurt their chances in the final quarter against the Suns.

"We thought the effort was there. As Scotty [Watters] said, our efficiency going inside 50 – I think we had 20-odd inside 50s in the last quarter – I think we were just too 'bomby'," he said.

"We didn't honour the forwards' leads and stuff so I reckon that's what let us down, as well as accuracy … that's been a bit of a problem over the last month or so.

"Especially in the last quarter, there were numbers back in our forward 50 and that makes it a bit hard, and the pressure has gone right up in the game these days.

"I think those are aspects that make players kick long under pressure."

Sam Fisher is a defender in NAB AFL Fantasy. He averaged 72 points in 2012. Register your team at our AFL Fantasy Hub.

Jennifer Phelan is a reporter for AFL Media. Follow her on Twitter @AFL_JenPhelan.