The MLB Draft League kicked off a week ago, with each of its six teams competing in its first action of the summer. Tonight, one of those teams, the Trenton Thunder, will feature 19-year-old Rintaro Sasaki, Japan's all-time high school home run record holder, who is making his United States debut right now vs. the Frederick Keys at Nymeo Field in Frederick, Md., and you can watch it for free right here.

Sasaki wasted little time making his impact felt, crushing a two-run homer to right field in the third. He also added an RBI single in the sixth that came off the bat at 105.7 mph.

Sasaki was projected to go first overall in the NPB Draft before pulling his name and enrolling at Stanford University. The 6-foot, 230-pound slugger attended the same high school -- Hanamaki Higashi High School -- as Shohei Ohtani and Blue Jays pitcher Yusei Kikuchi. Not only that, but Rintaro's father, Hiroshi, coached them all.

Ineligible to compete in collegiate baseball until next fall, Sasaki spent this past spring practicing with the Cardinal, working out and taking classes. His debut with the Thunder tonight marks his first official game in the U.S. He's expected to play first base for Trenton for the first half of the season, which concludes on July 13.

All MLB Draft League games stream live on the MLB Draft League site and on MLB.TV.

• What is the MLB Draft League?

In recent years, the MLB Draft League has served as a platform for international prospects to make a name for themselves, but never has it welcomed a player of Sasaki's magnitude.

The MLB Draft League is a six-team baseball league featuring a split-season amateur-professional format. The first half of the MLB Draft League season features Draft-eligible players aiming to improve their stock ahead of the annual MLB Draft in July. The League switches to a professional format in the second half, with paid players comprising the six rosters.