Fernandez, who will be a vital member of the Spanish squad at the EuroBasket Women in Italy later this summer, has signed a deal with the Los Angeles Sparks.
And with her European side UB Barcelona having had their Liga Femenina season ended by her former club Ros Casares at the semi-final stage, Fernandez has decided to join with her new club this week.
Fernandez, who was the most valuable player in the Spanish league last season, has not previously played in the WNBA but she is looking forward to the challenge.
"It is a great opportunity," said Fernandez. "I think that this is the perfect time to go, one year before the Olympic Games."
The 25-year-old won three Spanish tiles with Ros Casares and one with Barcelona, while she has also represented her country in almost 100 matches.
Her brother, Rudy Fernandez, helped Spain's men's team win the FIBA World Championship in Japan last year.
Team Bath Netball produced their highest-scoring performance of the Vitality Superleague season so far as they beat Sirens 63-47 to move up to fourth in the table.