"I tried it just one day and I loved it," she said. "It's really active and you get to a point where you've played enough basketball and volleyball and want something new."
The Australian-rules football club Casillas is a member of, the New York Magpies — which is the only of its kind in the city — will kick off its 2012 season June 15 and is looking for new players.
Footy, as the game is known, is a high-speed combination of soccer, American football and rugby, explained Australia native Myles Walkington, the Magpies' commissioner.
"Footy is a 3D game," he said. "It's not just two lines coming at each other. It's continuous and there's a fair amount of tackling involved."
The object of the game is for members of two teams to score as many goals as possible by kicking a ball between a set of posts at either end of a field. Players can move anywhere on the field, kick and run with the ball, and tackle.
Despite the roughness of the game, footy players don't wear pads.
What their male players are known for wearing, though, are sleeveless jerseys and shorts that look skimpy to American eyes.
It's always shocking for Americans to see how short Australian men wear their shorts," Casillas, 30, said.
"[The uniforms] are something that a lot of our female spectators are interested in," Walkington admitted.
The female players, whose competitive team is called the Lady Pies, wear the same uniforms, Casillas said.
The New York Magpies, which launched in 1997, are seeking male and female players age 18 to 50, at all experience levels. Starting June 15 and continuing for the next three Fridays, the league will host free men's contact games and co-ed, non-contact games.
Footy players don't need to be massive, they just need to be versatile, agile athletes, Walkington said. And the recreational teams don't take themselves too seriously, he added.
"We want to introduce new people to the game and to have a bit of fun," he said.
Casillas said she's looking forward to introducing new people, especially women, to the game.
"It's great to see how every player, whether or not they've ever played a sport, learns how to kick and handle," she said. "It all comes together for them."
She urged people unfamiliar with footy to give it a shot.
"Just because you didn't know what it was doesn't mean you shouldn't try it."
Prospective players can contact Myles Walkington at email@example.com for more information.