We are only months away from the World Cup kicking off in North America, with the United States hosting 78 of the 104 matches ... and USMNT member Diego Luna is well aware of the stakes ... telling TMZ Sports it's one of the biggest years for the sport stateside!!
We chatted with Luna out at LAX ... and he described the World Cup in the U.S. as a "once in a lifetime opportunity for us."
"I think for the country itself, it's a once-in-a-lifetime opportunity," Luna said.