Mittelstadt, Brown and Yamamoto were linemates and helped the United States win the bronze medal at the 2016 IIHF World Under-18 Championship. They combined for 34 points (14 goals, 20 assists) at that event.
\[RELATED: World Junior Summer Showcase schedule\]
"Me, [Brown and Yamamoto] made a lot of quick little passes, were moving and trying to find some open areas, and I think that's what we do really well together," said Mittelstadt, who had two goals and two assists Tuesday. "That's when I'm at my best."
Mittelstadt was an early cut from last year's Summer Showcase and didn't play at the 2017 IIHF World Junior Championship but appears determined to be an offensive leader for the 2018 WJC team.
"Last year wasn't how I wanted it to go, so I wanted to come here, make plays right away and try to get a little bit of redemption," he said. "The key I think is some guys have some unfinished business, so being able to come out and try to make some plays and get to play with [Yamamoto and Brown] helps a lot."
Brown had two goals and one assist, and Yamamoto had two assists.
Patrick Harper (Nashville Predators) had three points (one goal, two assists) Joseph Anderson (New Jersey Devils), and Maxwell Gerlach (2018 Draft eligible) and defenseman Dylan Samberg (Winnipeg Jets) scored. Jake Oettinger (Dallas Stars) made 22 saves.
Forwards Cliff Pu (Sabres) and Brett Howden (Tampa Bay Lightning) scored for Canada.
Here are four other things we learned Tuesday: