The 30-year-old Lillyman also had offers from other NRL outfits.
"I love this club and always will," Mannering said. "I'm keen to be a part of our future and have the greatest faith in the direction the club is heading.
"It's not just about football, though. I also have my family to consider. That was a big part of the decision and I'm really happy it has all worked out."
The timing of the announcement is significant and co-owner Eric Watson said the departure of Matt Elliott and appointment of Andrew McFadden as interim coach was important.
"Whether Simon would have re-signed or not is a moot point now but the reality is it would have been a blow for the Warriors if Simon had not re-signed," Watson told Newstalk ZB.
"There are always risks in football teams about who's staying and who's going. It certainly would have been destabilising and was something the board took into consideration when they decided to go with Andrew McFadden [as interim coach]."
Scurrah painted a different picture, saying most of the deals were done some time ago. Mannering and Lillyman signed this week.
"With what has happened during the week, we just wanted to reassure people," said Scurrah. "It's nonsense there's a player revolt and people didn't want to be here under Matt. Of course the coach is important and some prefer Matt or Cappy [McFadden]. That's life. It doesn't mean you want to up and leave the club."
Scurrah will depart if the Warriors don't make the playoffs this season. He offered to resign last season but was turned down by Watson who said it would be expected and accepted this time.
"I will step down if we don't make the playoffs this year," Scurrah said. "It won't be right for the club to not make the finals three years in a row and for there not to be a need for a change of direction at the top.
" I'm happy to put my nuts on the line and, when I hear there's no accountability in the club, Eric puts it on me all the time and I relish it. "
The Warriors play their first match under McFadden against the Bulldogs at Eden Park today.