Her school principal told her football wasn't for girls - she's now a doctor for a top women's club in England

It all began - oddly enough - on a basketball court at Raffles Girls' Primary School during the 2002 FIFA World Cup. Like many, 10-year-old Bethany Koh was caught up in World Cup fever.

Someone brought a ball to school, and Koh started playing football with her friends at every recess, going back to class sweat-soaked and exhilarated. That World Cup ended with Brazil winning, and Koh kept on playing.

In secondary school, she and her friends even tried to set up a girls' football co-curricular activity (CCA). They gathered enough girls to form an 11-a-side team and found a teacher willing to oversee the CCA.

But her principal shut the idea down because "football is not for girls". That did not quell her fire.

Koh continued playing at recess, and on weekends on fields in Bedok. "You just use your shoes as the goalpost," the 34-year-old Singaporean recalled with a laugh.

Bethany Koh (third from left), aged 12, at a football camp in 2004. There were 21 boys and three girls, including Koh.

She's not there as a player, but a first-team doctor caring for the competitive squad, helping them stay in peak condition. BEHIND THE SCENES ON MATCH DAY On Sep 27, Chelsea FC Women faced rivals Arsenal Women before nearly 20,000 spectators.

"Football is like a religion here," said Koh. As a first-team doctor, Koh was on the team bench - it's not always the best view because it is so low down, she said.

But she is there for the players, not the game. While the rest of the stadium was riveted on the ball, her eyes remained on the players.