By Christian Smith

It's been barely a week since the eyes of the sports world were focused on the the FIFA World Cup. Now rugby gets to step into the spotlight ー and very likely attract the most attention it has ever seen in the U.S.

The Rugby World Cup Sevens 2018 began Friday at AT&T Park in San Francisco. It's the largest rugby event ever in the U.S. with 64 teams competing in the men's and women's tournaments.

Hosting the tournament on American soil gives USA Rugby one of its best ever opportunities to grow the sport's presence and popularity in the U.S. USA Rugby Commercial Director Mark Griffin says the sport has already made major inroads into mainstream American sports culture since he arrived from his native England.

"I've been here 19 years, and I've seen major growth, probably a doubling, I think, in terms of the number of people involved in the game over that period of time," said in an interview on Cheddar.

Rugby sevens is a version of the game featuring smaller teams and shorter matches. In sevens matches, seven players play seven-minute halves, instead of the usual 15 players playing 40-minute halves.

To grow the game's presence in the country, Griffin says USA Rugby is working to boost the resources available for the national teams as well as get the game into the educational system from youth programs to college. "The college infrastructure in America is absolutely incredible and second to none," he told Cheddar.

USA Rugby's efforts are already paying off. Both the American men's and women's teams come into the tournament near the top of the pack. The women are ranked fifth in the world, and the men are ranked sixth.

While rugby's popularity will likely never reach the level of football in America, Griffin says it doesn't matter.

"We don't need to be the NFL ー we don't need to be any of the big major sports," he said. "There's enough people here that love what rugby stands for that we can carve out our own little niche."

Competition will continue through Sunday. The American women already notched a big 38-7 win over China. The American men are playing Friday night.

For the full segment, click here.