A school spokesman said Fernandez was admitted to the hospital for the night as a precaution. She is expected to make a full recovery.
The game was delayed about 30 minutes as emergency personnel treated Fernandez. Players from both sides huddled around her as she lay on the floor, azcentral.com reported.
The harrowing play happened in the first quarter. The arena was filled with youngsters for the afternoon game.
Fernandez, a 5-foot-10 guard from Hawaii, scored two points before getting hurt. She was averaging five points in eight games this season.
Sophie Brunner had 20 points and 15 rebounds to help the Sun Devils (13-3, 4-1 Pac-12) win their fourth in a row. Reili Richardson added 15 points, and Quinn Dornstauder had 11.
Chanelle Molina scored 13 points for Washington State (8-9, 3-3). The Cougars had won three in a row.