"It could be a four-weeker, it could be a 10-weeker.
"We just really have to wait and see on Monday.''
NSW Cup hooker Apisai Koroisau, who represented Fiji at last year's World Cup but is yet to play NRL, has emerged as a likely replacement for Luke.
In good news for Souths fans, Maguire said superstar Greg Inglis, who was knocked out in the fifth minute on Friday night and didn't return, would be fit for Souths' round four match with Canberra next Sunday.
"He will be fine,'' Maguire said.
"There probably was an opportunity to play him at the back end but our doc, obviously with things that are going on at the moment, thought it was best to keep him on the sidelines.''
The Rabbitohs led 6-0 when Inglis departed and again showed the struggles they have without him, but Maguire denied suggestion they are a one-man band.
"You take the best out of any team and it can have a reaction but you have to be able to handle that,'' he said.
"You have to find ways (to win) and we have the quality of players to be able to do that.
"As much as he was a loss, we should have grouped together and put on a better performance.''
Prop Aaron Woods claimed the Tigers successfully targeted Sam Burgess' indiscipline in their impressive win and Maguire admitted it was something he had to look at.
"As much as they are talking on the Burgesses, they are taking on our whole forward pack,'' he said.
- AAP
``We are not the first forward pack to face a few challenges.''
