The Major League players were never a part of it but lots of future stars played in them before they were major leaguers , Roy Oswalt, Dice-K, R.A. Dickey, Troy Glaus, Alexei Ramirez, Stephen Strasburg, Dexter Fowler and that's just since it's been official. The USA teams of the eighties thwhen it was a demonstration team were stacked especially the 1984 team had Will Clark, Mark McGwire and Barry Larkin. It's not a huge loss especially now that there's the WBC but it's certainly a shame for Japan where it would have been popular.