Valetini is on the Wallabies' radar as a back-row option for the spring tour squad and he had set his sights on using the National Rugby Championship to press his claims.

But the boom rookie limped from the field with another suspected knee injury during the Canberra Vikings' thrilling 24-17 win over the NSW Country Eagles at Armidale's Bellevue Oval on Sunday.

Wallabies coaches were watching closely as they continue to assess Valetini's spring tour prospects, with the 20-year-old only left out of the Wallabies squad announced on Friday because he is only one game into a comeback from a knee injury.

But watching him receive treatment on the field for almost three minutes was far from what they wanted to see.

"I hope it’s not too serious, he’s had enough of those," Canberra coach Nick Scrivener said.

"We’ve basically just packed up and gone, so we’ll get the assessments done and see if it’s the same exact injury [as the ones from earlier this year] or something related.

"We won’t know really, we’ll just get back and assess it on Monday. Hopefully it’s not too serious, we won’t know until we actually scan him."

The hulking 193 centimetre, 113 kilogram back-rower was dealt a cruel blow during his Super Rugby debut when he damaged his medial ligament earlier this year.

He returned three months later, but Valetini could only get through two games before suffering a Super Rugby season-ending knee injury.

The prospect of another injury for the rising star that has been earmarked as an option for next year's World Cup is devastating for the Vikings, who just managed to sneak away with the points after he left the field thanks to an 83rd minute try to Jordan Jackson-Hope.

Down by 14 entering the second half, the Vikings turned to Valetini to provide some spark and he crashed over for a try to give Canberra a ray of hope.

Things went awry soon after when Valetini limped off the field, but it failed to disrupt the Vikings as Lausii Taliauli strode down the sideline to score and Wharenui Hawera levelled the scores just moments later.

The Eagles kicked three points clear before Hawera struck back to tie things up in the dying stages.

With the game on the line Canberra were pressing hard and calling for someone to stand up. Enter Jackson-Hope, the dashing inside centre that split the Eagles defence in half to score a match-winning try.

"I don’t think we played particularly well at all in a lot of facets of the game but we stuck in there and we were good enough in a few moments that counted," Scrivener said.

"We scored when we needed to. Really pleased, to not put in your best performance but to win the game was great.

"I think this little block of the games, this week and the next week or two, everything is going to start settling down and it will be pretty clear who is going to be where.

"Certainly for the Country Eagles, they were pretty desperate to win to stay in touch with the finals. Any victories around this period is really important."

AT A GLANCE

NRC round 4: CANBERRA VIKINGS 24 (Valetini, Taliauli, Jackson-Hope tries; Hawera 3 conversions; Hawera penalty goal) bt NSW COUNTRY EAGLES 17 (Penalty try, Newsome tries; Mason conversion, Mason penalty goal) at Bellevue Oval.