South Sydney halfback Adam Reynolds out for a month

South Sydney's NRL campaign has been dealt an early blow after halfback Adam Reynolds was ruled out for up to a month following knee surgery.

Reynolds suffered the injury in the first half of the Rabbitohs' season-opening loss to the Warriors in Perth. It was later revealed he would need an arthroscopy.

Teammate Dane Gagai praised Reynolds for finishing out the match under duress.

"He mentioned he had a bit of a problem but I didn't know it was as serious as it was," Gagai said on Tuesday. "He's an outstanding player and plays above his weight. He toughed it out. He pushed through the game and I thought he done a great job there.

"It's disappointing but we've got to move forward and whoever plays that role I know is going to do a good job."

The injury is a bitter blow for the Rabbitohs, who had just celebrated the return of skipper Greg Inglis from a knee reconstruction which limited him to just one game last year.

Reynolds' absence could open the door for the return of veteran Robbie Farah, who played a trial game at halfback and was omitted from their defeat to the Warriors. Another option for rookie coach Anthony Seibold is youngster Adam Doueihi, who was Farah's halves partner for Lebanon during the World Cup and was in Souths' 19-man squad last week.

Five-eighth Cody Walker said he is ready to shoulder the playmaking duties in the absence of Reynolds.

"Reyno's the chief playmaker in our side and it's my turn to step up," he said. "I played halfback when (Reynolds) was out a couple of games there (last year); I think the Brisbane game I played half with (John Sutton). It's something I need to do this weekend."

Walker insisted Farah could handle a shift to halfback.

"He'd be raring to go. He's an experienced campaigner and he could definitely do that," he said.