Antonio Freeman Says He Couldn't Be Prouder Of Son Alex Living Out World Cup Dream

Antonio Freeman says his son Alex Freeman, the youngest player on the United States soccer team, is living out his dreams on the soccer pitch, playing in the FIFA World Cup ... and his former Packers star pops couldn't be happier!

"I'm a proud dad, I'm proud of Alex. You know, this was his dream. This was his journey," the retired NFL star told TMZ Sports Wednesday night, on the eve of the team's last Group Stage match.

"And, man, [Alex] worked tirelessly when no one was watching, when everybody else was partying. You know, he was looking forward to those training sessions. And as a dad, to say I'm proud is an understatement. This is unbelievable. Unimaginable."

All this, of course, coming from a guy who played on the biggest stage ... but Antonio says nothing he did on the gridiron -- including an 81-yard touchdown reception from Brett Favre in Super Bowl XXXI -- comes anywhere close to the joy he's now feeling.

Alex, a 6'2" super athletic defender, has become one of the breakout stars of the tourney ... especially after scoring a goal against Australia.

"To be the youngest kid on the team, and be ready for the moment and just capture the attention of the United States and people all over the world. It's exciting to watch," Antonio said.