2011-12: Juho Lammikko appeared in two games with Assat Pori’s U20 team in Finland as a 16-year-old and was the leading scorer for the club’s U16 squad. He had 1 assist in two games with the Assat U20 team and also had an assist in two games with the club’s U18 squad. Lammikko led all players in Finland’s U16 Division 1 with 52 goals in 26 regular season games and had 51 assists and 40 penalty minutes. In five qualifier games he scored 7 goals with 8 assists. In the Division 1 playoffs he finished with 11 goals and 15 assists and had 9 penalty minutes in nine games. Lammikko played four games for Finland’s U16 team and was +3 with 2 assists.
2012-13: Lammikko skated in 15 games for Assat’s U20 team and was the top scorer for he club’s U18 team. He represented Finland in the 2013 U17 World Hockey Challenge. Lammikko had 1 assist with 10 penalty minutes and was -4 for the Assat U20 squad; which missed the playoffs after finishing 13th in the 16-team league. Lammikko scored 21 goals with 32 assists and had 22 penalty minutes in 31 regular season games for Assat’s U18 team. In nine playoff games he scored 5 goals with 6 assists and 12 penalty minutes. Lammikko had 6 assists and 2 penalty minutes in five games at the WHC.
2013-14: Lammikko represented Finland in the 2013 Ivan Hlinka Memorial Tournament before returning to Assat — splitting the season between the men’s team and the U20 squad — and finished the season with the Finland U18 team at the 2014 World Juniors. Making his Liiga debut in September as a 17-year-old, he had 1 assist and was -4, averaging under eight minutes of ice time in 20 games. Lammikko scored 17 goals with 25 assists and was +24 with 32 penalty minutes in 37 A juniors regular season games and had 3 goals with 5 assists while finishing -6 with 28 points in 11 playoff games as the squad won the bronze medal. Lammikko scored 3 goals with 3 assists and was +3 with 6 penalty minutes in four games at the Ivan Hlinka Tournament and scored 2 goals with 4 assists and was +1 with 2 penalty minutes in five games at the WJC. Lammikko was ranked 14th amongst European skaters in the Central Scouting final rankings and was selected in the third round (65th overall) in the 2014 NHL Draft.
2014-15: Lammikko played with eventual Panthers prospect Lawson Crouse on the Kingston Frontenacs and accumulated 44 points in 64 games in his first year in North America. He was also a plus-23 player and recorded 36 penalty minutes. In four playoff games his stat line was much worse as he collected just two points and was a minus-5.
2015-16: Lammikko began the season in Finland, skating in five Liiga games with Assat Pori before returning to Kingston for his second OHL season. He played for Finland at the 2016 World Junior Championship and made his North American pro debut in April, joining Florida AHL affiliate Portland along with Frontenacs’ teammate Lawson Crouse. He was +1 with no points and 2 penalty minutes in his only game with the Pirates. Lammikko scored 2 goals with 4 penalty minutes skating for Assat, averaging 11 minutes of ice time. He scored 22 goals with 33 assists and was +24 with 51 penalty minutes in 59 games for Kingston. The Frontenacs finished first in the East Division and reached the second round in the playoffs. Lammikko scored 3 goals with 4 assists and was +1 with 6 penalty minutes in nine playoff games. Playing for the gold medal Finland U20 squad he was +2 with no points and 2 penalty minutes in seven games at the WJC. Finland defeated Russia, 4-3 in overtime, in the gold medal game. Lammikko signed a three-year entry-level contract with the Panthers in April 2016.
Lammikko is frequently compared to 2011 Chicago first-round pick Joel Armia since both are tall, right-handed shots and both are from the same Assat club. Those comparisons are a bit erroneous. More of a late bloomer than Armia, Lammikko is still developing as a prospect. Dominant offensively at the junior levels, he has yet to put up the numbers that Armia did at the same age for the Assat men's team. At the same time, Lammikko's defensive game with Kingston has been more advanced than Armia's was at the same age. In addition to his obvious physical attributes, the things that have drawn interest from scouts are Lammikko's skating ability, passing skills, and anticipation. Agility and physical strength are areas that will need to continue to develop; not unusual for taller players his age.
Lammikko returned to Kingston for his second season with the Frontenacs in 2015-16 after a brief five-game stint with Assat in Finland to start the year. He skated for the gold medal Finland team at the 2016 World Juniors and signed an entry-level contract with Florida in April 2016. A reliable two-way forward who can score at times, his role at the pro level is likely to be that of a Jere Lehtinen-type winger, though he may not score with the same consistency as the former Dallas Stars forward.