The Oilers selected the forward 22nd overall in the 2017 NHL Draft in June.
The 18-year-old played 65 games with the Western Hockey League’s Spokane Chiefs last season, scoring 42 goals and 99 points.
Yamamoto, who turns 19 next month, was also named to the 2016-17 WHL Western Conference Second All-Star Team.
The 5’8″, 153-pound forward has appeared in 190 career WHL games, accumulating 227 points and 130 penalty minutes.
The Spokane, Wash. native attended the Oilers 2017 Development Camp in Jasper this summer.