South Sydney duo Adam Reynolds and John Sutton could face extended stints on the sideline after suffering injury in the Rabbitohs big NRL win over Sydney Roosters.

Souths thumped their arch rivals 42-10 at Allianz Stadium on Sunday before 25,125 fans, but a jaw injury to Reynolds and a pectoral problem for Sutton significantly soured the confidence-boosting win.

Reynolds’ kicking game played a significant role in leading the Rabbitohs to a 26-0 halftime lead, while he also laid on tries for Paul Carter and Alex Johnston.

But the premiership-winning No.7 went down in the 58th minute in an innocuous-looking tackle on Kane Evans and Sutton went off soon after to give coach Michael Maguire plenty of cause for concern.

“They will have scans in the next couple of days to determine the extent of those injuries,” Maguire said.

“Adam was smiling in the change room, so hopefully that means something.”

The results of those scans could be known as soon as Monday.

Early indications are Reynolds could miss between six weeks and five months, while Sutton’s time out of the game could be between four and five months.

Those injuries put a significant dampener on an impressive first-up effort from Souths in Sam Burgess’ comeback game to the NRL.

“I thought the boys were very thorough,” Maguire said.

“I am proud of the way they have prepared for the season, the boys have worked hard but the results of the hard work were there.”

Souths captain Greg Inglis was equally effusive.

“I thought it was an outstanding effort,” he said.

Roosters coach Trent Robinson had less to work with.

Two tries on his NRL debut to Englishman Joe Burgess, who came into the side after Daniel Tupou withdrew with an ankle injury, and the efforts of Shaun Kenny-Dowall, who was the Tricolours’ best, were among the few positives Robinson could take from the thrashing.

“We gave them the ball through errors and penalties and poor kicking and that was our boat for the first 20 minutes and we didn’t deal with it well,” he said.

“We needed to defend our line better than we did. They fought hard for our tries and we gave them up too easily. We were not good enough.”

Robinson refused to blame the Roosters’ off-season woes or the loss of key personnel through injury and suspension for the big loss.