The reigning national champion UCLA women’s basketball team has suffered a big blow a month before opening its title defense.

The Bruins announced on Sunday that sophomore guard Lena Bilic — a likely starter on a team that must replace its top six players — would miss the entire season after suffering a torn anterior cruciate ligament in practice.

“We are devastated for Lena,” coach Cori Close said in a statement. “She is such an important part of what we do here, and I know she’ll continue to be impactful for us through her recovery. We’ll be with Lena every step of the way, and she’s in great hands with the best medical staff in the country, so I know she will come out on the other side stronger and better.”

Playing exclusively off the bench as a freshman while averaging 12.1 minutes on a loaded roster, Bilic showed enticing glimpses of her potential in a larger role.

She scored in double figures three times, including a 13-point outing against Oregon in her team’s Big Ten Conference opener. Known for injecting energy and making hustle plays, Bilic finished the season with 13 steals, nine blocks and 21 assists.

Her absence means that the Bruins must rely even more heavily on a transfer class that includes guards Elina Aarnisalo (North Carolina), Donovyn Hunter (TCU), KK Bransford (Notre Dame) and Bonnie Deas (Arkansas). UCLA also brought in freshman guard Somto Okafor.

The Bruins will need lots of newcomers to step up after losing center Lauren Betts, forward Angela Dugalic and guards Kiki Rice, Gabriela Jaquez and Gianna Kneepkens to the WNBA.

UCLA is scheduled to play Cal in an exhibition on Oct. 14 before opening its season against Lehigh on Nov. 2. The Bruins will hold a ring ceremony and raise their championship banner before facing Princeton on Nov. 15.