Chelsea are leading the race to sign San Diego Spurs center back Naomi Gilma, sources have told ESPN, while Arsenal and Lyon are also interested in the US Women's National Team star.

Gilma, 24, is contracted to the NWSL until 2026, so any deal would require a substantial transfer fee. A source told ESPN that this could become the first $1 million transfer in women's soccer history.

Gilma is one of the highest-rated defenders of the modern era and played a major role in helping the U.S. women's soccer team win a gold medal at the 2024 Paris Olympics.

Manager Emma Hayes said Gilma is "the best defender I've ever seen. I've never seen a defender as good as her."

Chelsea head coach Sonia Bompast admitted she is looking to strengthen her centre-back options after Canadian defender Kadesha Buchanan suffered an anterior cruciate ligament (ACL) injury, with some sources telling ESPN Gilmar is theirs First choice.

Bompasteau's former club Lyon (owned by businesswoman Michelle Kahn) have also expressed an interest in the centre-back, despite signing a deal with Swedish defender Elma Judila Nel earlier in the transfer window. Hager struck a deal.

Meanwhile, another source told ESPN that Arsenal, who have been keeping an eye on Gilma for some time, have also expressed interest in bringing in the centre-back.

There will be some obstacles, though, not least the transfer fee required to poach one of the best players in the world from the San Diego Waves. Former Arsenal manager Jonas Eidevall is the new manager of Santiago Bo and he is unwilling to leave the club in a difficult situation after it was taken over by the Leichtmann-Lewin family in October. Losing a quality player like Gilmar under new ownership.

The Wave has parted ways with Jaedyn Shaw since Eidevall took over last week. The 20-year-old forward transferred to the North Carolina Courage in exchange for $300,000 in allotted funds and an intra-league transfer fee of $150,000, as well as international travel to San Diego in 2025 and 2026.

The current world record for transfer fees in women's football is held by Racheal Kundananji, who moved from Madrid CFF to Bay FC for $860,000. Given Gilma's talent, her transfer fee will likely need to exceed the current record to give the team value for money.

Girma won NWSL Defender of the Year in 2022 and 2023, but lost to Emily Sans in 2024.