The Vikings are clinging to their faint National Rugby Championship finals hopes after they were beaten by the NSW Country Eagles 42-37 at Viking Park on Saturday.

They need to win their last game against Brisbane City and rely on the Eagles beating the Perth Spirit to snatch an unlikely play-off berth.

Mogg's absence will leave a hole at the back and the Brumbies searching for a new No.15 for the start of their 2015 Super Rugby campaign.

Mogg still has ambitions to play for the Wallabies at the World Cup next year and his NRC season was cut short to ensure he misses minimal Super Rugby action.

It's the second time in 13 months Mogg has been forced to have a shoulder reconstruction, this time on his right shoulder and he could be on the sidelines until April.

"It's frustrating to be injured for a long time, but one of the discussions we had was to miss a couple of games at the start [of Super Rugby] rather than getting three games into the season and then blowing it out," Mogg said.

"Especially leading into the World Cup. I still have ambitions to get back in the [Wallabies] squad. Timing for this was key and getting surgery now was in the best interest of getting right for Super Rugby."

Mogg was absent for the Vikings' five-point loss to the Eagles in a game which boasted Wallabies Nic White and Josh Mann-Rea in the NSW Country line-up.

Mann-Rea played 50 minutes while White came off the bench in the second half as the pair prepare to join the Wallabies camp in Brisbane on Sunday.

The Vikings trailed by 21 points with less than 20 minutes remaining, but launched an inspired comeback with time running out.

Isaac Thompson and Joe Powell scored tries in the final 10 minutes to lift Canberra within five points, but their last-minute charge fell short when they lost the ball with the try-line in sight after the siren.

The Vikings' scrum dominated the game and Robbie Coleman was strong at fly-half, but simple errors cost the home side a chance to all but secure a finals spot.

Canberra will play Brisbane City at Suncorp Stadium as a curtain-raiser to the Wallabies-All Blacks Bledisloe Cup match next weekend.

"We dug deep, Country could have wiped us off the park but we hung in there," said Canberra captain Fotu Auelua.

"Individually we've got some brilliance, but we just have to gel together as a team."

AT A GLANCE

NSW COUNTRY EAGLES 42 (Andrew Kellaway 2, Mitchell Chapman, Tala Gray, Ethan Ford, Apakuki Ma'afu tries; Sam Windsor 4 conversions) bt CANBERRA VIKINGS 37 (Jarrad Butler, Michael Henry, Tim Cree, Isaac Thompson, Joe Powell tries; Isaac Thompson 2, Rodney Iona conversions) at Viking Park.