2007-08: In 35 games with JYP's U20 squad, the D-man scored nine goals and 29 assists. He also competed with Finland's national team at the U18 WJC, registering three helpers in six games.
2008-09: Suited up for 20 games with JYP in the U20 SM-Liiga, posting three goals and seven assists. Captained the Finnish entry in the U18 World Championships, winning a bronze medal in the process.
2009-10: Playing for JyP HT Jyvaskyla of the Finnish league, Vatanen posted 7 goals, 23 assists, 44 PIM, and 4 powerplay goals. He also registered 324 shots. He also represented Finland at the WJC where he posted 2 goals and 3 assists in 6 games. At the end of the season, he skated for Finland at the World Cup, where he went scoreless in 7 games.
2010-11: Vatanen was an offensive catalyst from his defense spot as a 19-year-old in his second season with JyP, the top team in Finland's SM-Liiga. JyP finished with 129 points – ten points ahead of second-place Assat Pori and Vatanen was a team-leading +30 plus/minus with 11 goals and 20 assists in 52 games. He was +4 with 1 goal and 1 assist in three playoff games before suffering a leg injury that kept him out of the remainder of the playoffs and the 2011 IIHF World Championship. Vatanen played for Finland at the 2011 U20 World Junior Championship and was +7 with 4 assists. He signed a three-year, entry-level contract with Anaheim in May 2011.
2011-12: Vatanen was the second-leading scorer among defensemen in Finland's SM-Liiga behind veteran Toni Soderholm. He scored 14 goals with 28 assists in 49 games in his third season with league champion JyP. Vatanan missed time mid-season with a broken finger and also suffered a leg injury during the SM-Liiga playoffs that limited him to four games. JyP defeated Pelicans in the Kanada Cup finals after finishing fourth in the regular season . Vatanen scored 2 goals and was plus-two with 4 penalty minutes in the playoffs. His injury kept him out of the 2012 U20 IIHF World Championship – which was co-hosted by Finland and Sweden.
Vatanen has game-breaking potential with his speed, imagination and seeing-eye wrist shot. As a puck-carrying, puck-moving defenseman, his skills are on par with the best prospects out there. Vatanen remains rather undersized, which will present a major obstacle as he transitions onto North American ice.
Already prospering in Finland’s top professional league, Vatanen has proved he can play among fully developed opponents. Whether or not he is capable of doing so in the world’s greatest league remains to be seen. Vatanen could be a dynamic No. 2 defenseman, or he could spend his entire pro career in Europe.