Canberra's forward depth will be tested after losing rookie front-rower Ata Mariota to a broken hand during the Canberra Raiders' 20-14 loss to the Dolphins in Redcliffe.

After making a singular NRL appearance as an 18th man replacement last season, 21-year-old Mariota won a bench spot over the off-season on the back of some strong performances in the pre-season challenge and NSW Cup last year.

Currently without Josh Papalii due to a calf complaint, Mariota's impact off the pine has been integral over Canberra's first two losses, both defeats snatched from the jaws of victory after sitting level in the dying moments.

The rookie made 75 metres and 27 tackles in just 24 minutes against the Dolphins before being dragged from the field with an injury.

Scans have revealed a broken hand for Mariota, who will now spend at least a month on the sidelines after being handed a six to eight week recovery period for the setback.

The Raiders have confirmed they are expecting him to be fit again between Round 8 and 10.

It's just more weight on Joseph Tapine's shoulders as the Kiwi international continues to spearhead an undermanned forward pack, although there is hope that Papalii may face Cronulla this weekend.

The Raiders don't play until the final match of the round, giving the Samoan international another six days to recover from his calf injury and line-up in Canberra's first home game this season.

It'll be a welcome return for the Raiders, who have spent the opening fortnight of the season playing in Queensland, although it does get two tough road trips out of the way early in the year.

Trey Mooney shapes up as another potential replacement on the bench for Canberra if Papalii isn't fit to return, joining middle forwards Tapine, Corey Horsburgh, Emre Guler and Pasami Saulo in the 17.