The Lightning are ranked No. 1 in CIF Southern Section Division IV-AA.
"We don't have the big hitters we had last year, so we'll have to be a better defensive team," Thomassen said. "We'll win points by making fewer mistakes than the other team. We have to be patient and get the points whenever we can, off serving and well-placed hits."
Senior Kelsey Lawler will help with the latter. Lawler, 5-foot-7, returns at setter after garnering first-team All-Academy League and first-team All-CIF honors last year.
"She's not an imposing player but she's very smart and a very good leader on and off the court," Thomassen said. "That's important, because we have a lot of kids new to the varsity. She'll be teaching and leading."
Fellow senior Kelly Hutchinson, 5-9, was second-team All-Academy League last year as a right-side hitter. Hutchinson is in her third varsity season.
"She always seems to be on the court when good things are happening," Thomassen said. "She makes big plays."
Amanda Tjan, also a senior in her third varsity season, is one of Sage Hill's best defenders. The 5-7 Tjan was a second-team All-Academy League selection last year, and she teams with Lawler and Hutchinson to form a proven nucleus.
"I'm relying on those three a lot," Thomassen said. " Not only for good ball-control and good defense, but also for their leadership qualities."
Outside hitter and libero Mackenzie Bronk and opposite Colleen Heyler, both juniors, also return.
Thomassen said he has three middle blockers competing for two spots, including sophomores Victoria Senechal and Katherine Bukaty, as well as freshman Madison Gordon.
Another freshman, Lindsey Kish, should also contribute, Thomassen said.
"[Kish] is a well-rounded player," Thomassen said. "She has pretty good ball control. She'll be playing a variety of positions, mostly outside hitter."