Raiders hooker Saliva Havili.

Canberra hooker Siliva Havili knew he could have been either the "hero or the villain" with his field goal attempt from dummy half late in his side's heartbreaking loss to Penrith on Friday night.

Up by six with as many minutes left to play against the ladder leaders, the Raiders looked a chance to pull off what would have been their biggest win of the season.

Havili admitted he lost track of the tackle count, saying he did not realise it was only the fourth when his shot went under the crossbar from 15 metres out.

"I knew I wanted to seal the game and I talked to Aidan Sezer the set before that and early in the next set we got a penalty I told him we'd try and get a field goal in that set," Havili said.

"I wasn't aware of the tackle count, but I saw Aidan play the ball and I thought I'd have a crack (at a field goal).

"I got up to pass and it didn't come off right. We talked about it in our review and you can be the hero or the villain, and unfortunately, it didn't come off."

The loss puts the Raiders' backs to the wall for much of the rest of the season if they want to play in the finals.

Since 2010, the team finishing in eighth has earned at least 27 competition points. To reach that mark the Raiders would need to win around eight of their last 11 games.

"They're games that aren't easy to take and we've had a few of them now," Blake Austin said after Canberra's latest close defeat.

"We came in today and had a look at the game, but I think it's our job to make sure we keep ourselves in the fight every week and look to get a little bit better each week.

"We're in the games up to our eyeballs every week which is what makes it hard."

This week Canberra takes on a Wests Tigers side desperate to hang onto their place in the eight.

To do so they will have to rely on the relatively new halves pair of Josh Reynolds and Luke Brooks after Benji Marshall was ruled out for six weeks due to a calf injury.

"I don't think they'll miss a beat with Benji out; Josh is a high-energy player so somebody we'll have to do our homework on," Austin said.

"Luke Brooks has probably been one of the form halfbacks of the competition so we're going to have our work cut out for us."

Canberra will be forced to make several changes of their own this weekend with Joe Tapine coming back in for the suspended Charlie Gubb, who took the early guilty plea for his dangerous tackle on Penrith's Nathan Cleary, while Michael Oldfield is likely to come in for the injured Jordan Rapana who will miss eight weeks with a torn hamstring.

"It's definitely disappointing for Jordan, Oldy's been in and around the team for a long time so it'll be great for him to get an opportunity," Austin said.

"It's been a really tough role for Oldy, he misses a bit of Mounties footy here and there to cover for us but anybody who knows Oldy knows he's a great team man and we'd love nothing more to see him play well now he's got his opportunity."

It was a whirlwind week for Nick Cotric who experienced the highs of being in the New South Wales squad ahead of their State of Origin I win before the latest late loss for the Raiders.

"It makes you hungrier to get out there and to keep working and never be comfortable in this grade, so you have to keep working hard and improving on the little things each week," Cotric said of trying to break into the NSW 17 this year.