Reinhart, the Oil Kings' captain who was selected No. 4 by the Islanders in the 2012 NHL Draft, had three assists and was a plus-1 in five tournament games.
"It's an unbelievable feeling," Reinhart said. "It's not too often that you get to compete for a championship like that, let alone get a second opportunity. We learned a lot from the first year I was there and applied that to this year."
Reinhart had 21 points in 45 games during the regular season and 13 points in 21 playoff games to help lead Edmonton to the Western Hockey League championship and a spot in the Memorial Cup. He was named WHL finals MVP with three points in the Oil Kings' 4-3 series win against the Portland Winterhawks.
Reinhart will likely have an opportunity to make the Islanders out of training camp next season.
"My focus is my defensive game," Reinhart said. "That's where I take a pride in and that's where I'm trying to get better at. I know I'm not going to go into the NHL and produce a bunch a points and lead any team in scoring. That's not my role, so just trying to shut down other teams' lines and make it harder for other teams to play."