LeBron James Would Be 'Baller' For USMNT In His Prime, Says Diego Luna

LeBron James was quite the football player in high school ... but how about football?? USMNT player Diego Luna tells TMZ Sports he woulda been a BEAST on the pitch in his prime!!

There's always an athlete claiming they could dominate another sport ... so when we ran into Luna at LAX this week, we had to ask which American jock could actually pull it off for the Red, White, and Blue.

"LeBron man, put him up top," Luna said. "Scoring goals, just bossing people around. That would be pretty sick."

Of course, Luna -- a two-time MLS All-Star -- is envisioning a younger James. LeBron is turning 41 this December ... and just started his 23rd season in the NBA -- the first player to ever reach the milestone.

"In his prime, he'd be a baller, for sure," Luna said.

James was a versatile athlete back at Akron's St. Vincent-St. Mary High School. Remember, outside of basketball, LBJ played wide receiver on the football team. Some believe he was so good, he could've played in the NFL.