2009-10: Mika Ilvonen played in 28 games, including three playoff contests, for the Espoo Blues U16 team as a 14-year-old. He had 9 assists and 8 penalty minutes. Ilvonen was invited to the Pohjola Camp for the top 15-year-olds in Finland and was named to the camp all-star team.
2010-11: Ilvonen skated for the Espoo Blues U18 and U16 teams — both of which won championships — and played for the Finland U16 team. He scored 1 goal with 4 assists and 10 penalty minutes in 15 games with the Blues U18 team during the regular season and had 1 assist and 2 penalty minutes in 11 playoff games. Ilvonen scored 1 goal with 8 assists and 6 penalty minutes in 13 regular season games for the Espoo U16 squad and scored 2 goals with 1 assist and 4 penalty minutes in six playoff games. He had 2 assists and 4 penalty minutes in 14 games for the Finland U16 team.
2011-12: Ilvonen appeared in four games with the Espoo Blues U20 team and was a key member of the Blues U18 squad as it won a silver medal in the B juniors playoffs. He was an assistant captain for the Finland U17 team. Ilvonen was +1 with no points and 2 penalty minutes in A junior play. He scored 2 goals with 13 assists and 18 penalty minutes in 32 regular season games for the Espoo U18 team and scored 2 goals with 7 assists and 4 penalty minutes in 13 playoff games. He had 8 assists and 6 penalty minutes in 19 games with the Finland U17 team.
2012-13: Ilvonen skated for Espoo Blues silver medal-winning U20 squad and played for the Finland U18 team in the 2012 Ivan Hlinka Memorial and 2013 World Junior Championship tournaments. He scored 2 goals with 11 assists and was +18 with 16 penalty minutes in 44 regular season games for the Blues U20 team and was +10 with 2 goals and 8 penalty minutes in 11 playoff games. Ilvonen had 4 assists and was +1 with 2 penalty minutes in five games at the Ivan Hlinka tournament. He had an even plus/minus with 1 assist and 2 penalty minutes in seven games as Finland won a bronze medal at the 2013 WJC. lvonen was selected by the Tri-City Storm in the 24th round (347th overall) of the 2013 USHL Entry Draft. He was ranked 118th amongst international skaters in the CSS final rankings but was not selected in the 2013 NHL Draft.
2013-14: Ilvonen chose to skate for the Espoo Blues U20 team to preserve his NCAA eligibility rather than playing with the Espoo men's team in Liiga and in December he committed to playing at St. Cloud State in 2014-15. He was the second-leading scorer for regular season and playoff champion Espoo and led all A juniors defensemen with 49 points (14 goals, 35 assists). Ilvonen was a league-leading +48 with 34 penalty minutes in 45 regular season games. In seven playoff games he scored 2 goals with 3 assists and was +6. He skated in three games for the Finland U20 team and was +3 with no points nor penalties but was not part of the squad that won a gold medal at the 2014 World Junior Championship in Stockholm.
Ilvonen is a skating defenseman who excels in the offensive aspects of the game and he likely would have competed in Liiga in 2013-14 if he had not chosen to pursue a college hockey career. Small and light, his size and strength will be a source of concern and he will need to prove he can succeed at the college level despite his size to have a shot at pro hockey.
Ilvonen will head to Minnesota in the fall to skate for St. Cloud State University — which competed in the NCAA tournament this spring. While the college game is still a couple of steps below NHL hockey, he will have time to continue to develop his game and adapt to North America. His success or failure at the college level will provide insight into his long-term pro potential.