"If it was me making the decision, I would probably give them up until Thursday.
"They have been training well all pre-season and I would like to see them get out there for the game.
"It's not ideal but these things happen in rugby league - that's just the way it goes."
After successive preliminary final losses to Manly and Canterbury, Maguire saw the need to re-style his side, especially in attack, ahead of 2014.
The injury to Keary especially has threatened to unravel months of hard work but Sutton showed in the Charity Shield win over St George Illawarra he remains a quality playmaker at No.6 where he has spent the majority of his 207-game NRL career.
Sutton's move to the forwards was not just about keeping the size in a pack that lost Roy Asotasi, Jeff Lima and Michael Crocker at the end of 2013 but also about creating attacking options in the middle of the park.
"That was the plan," Sutton said.
"I have done most of the pre-season training in the 13.
"I like to think I can run the ball hard but, in saying that, there might be a bit more ball playing through the middle.
"But I am comfortable playing six if I do have to play there."
Back-rower Ben Te'o said he would like to see Sutton remain in the Rabbitohs' pack.
"'D Walks' has been training in the halves all off-season; it is part of his development," he said.
"He is a great runner, a great ball runner and it is about getting him more involved.
"'Sutts' definitely has a lot to offer in the forward pack."
Greg Inglis could emerge as a shock halves option if Reynolds and Walker are both ruled out.
The superstar fullback played as a pivot in Melbourne when Maguire was assistant coach.
Tom Burgess (foot) is another injury worry for Souths.
In contrast, the Roosters are likely to have 16 of their premiership-winning 17 on the park with just the retired Luke O'Donnell absent.
"It's a great way to start the season against the reigning premiers," Sutton said.
"They played well in the World Club Challenge so I'm expecting a big game from them."
- AAP
