2006-07: A long-time defensive stalwart on TPS junior teams, Joonas Jarvinen had always grown earlier than his peers, which reinforced his role as the leader of the defense. Järvinen’s abilities carried over to international ice, where he captained the Finnish team on occasion. An assistant captain for TPS U20 team as an 18-year-old he scored 2 goals with 4 assists and had 26 penalty minutes in 37 regular season games. In five playoff games he had 2 goals with 1 assist and 2 penalty minutes. He skated for Finland at the 2007 U18 World Junior Championship and was minus-two in six games with no points and two penalty minutes.
2007-08: Despite the turmoil and frustration of TPS’ tenth-place SM-Liiga finish, the continued development of Jarvinen was one of the few bright spots in an otherwise forgettable season. Playing alongside veterans Aki-Petteri Berg and Marko Kiprusoff, as well as import Lee Sweatt, Jarvinen appeared in 50 games; scoring 1 goal with 3 assists and was minus-seven with 14 penalty minutes. In two playoff games against HIFK he was plus-one with 1 assist. Jarvinen played for Finland at the 2008 U20 World Junior Championship – finishing with no points and 2 penalty minutes in five games.
2008-09: Jarvinen emerged as a top four SM-Liiga defenseman in his second season with TPS and played for Finland in the 2009 U20 World Junior Championship. Showing steady play and utilizing his large frame, he displayed an excellent sense of positioning; stifling opposition attacks and blocking shots or passes. Despite a second straight 10th-place finish, TPS showed steady improvement – sweeping HIFK in the playoff qualifying round and taking eventual champion JyP to six games in the second round. TPS limited JyP to 3 goals or less in all but one game. Jarvinen was an even plus/minus with 1 assist and 6 penalty minutes in eight playoff games. Inn six games for Finland, which finished seventh in the WJC, he was minus-two with 2 assists.
2009-10: Jarvinen was a steady defensive defenseman for TPS in his third season as the Turku club captured an unlikely Kanada Cup championship following a sixth-place finish in the regular season. Playing with a physical edge to his game, he was third on TPS with 70 penalty minutes in 50 games and was plus-12 with 2 goals and 3 assists. TPS won the title beating another unlikely finalist, fourth-place HPK. Jarvinen had 1 goal with 3 assists and was plus-one with 16 penalty minutes in 15 playoff games.
2010-11: Jarvinen was one of the few players to remain with TPS following the championship season as most of the club's top players received big contract offers elsewhere. As a result TPS slipped to 13th place in the 14-team league – missing the SM-Liiga playoffs. Jarvinen contributed a career-high 11 points (4 goals, 7 assists) and was second on the team with 85 penalty minutes in 50 games. His minus-four plus/minus was one of the better marks on a team that won just 20 games and narrowly edged Pelicans to avoid the relegation playoffs.
2011-12: Jarvinen was re-united with former TPS coach Kai Suikkanen, moving to Lahti to play for Pelicans in his fifth SM-Liiga season. Jarvinen was a big part of the turnaround as Pelicans went from last place to second. He had career highs in points, plus/minus and penalty minutes – scoring 5 goals with 18 assists in 57 regular season games and finishing plus-28 with 125 penalty minutes. Pelicans reached the playoff finals and he was the second-leading scorer among defensemen with 3 goals and 3 assists. Jarvinen was plus-2 with 16 penalty minutes in 17 games. He was selected to play for Finland at the 2012 IIHF World Championship and had 3 assists, finishing plus-one with 4 penalty minutes in ten games Finland co-hosted the tournament with Sweden and finished fourth after falling to the Czech Republic in the bronze medal game. Jarvinen signed a two-year, two-way contract with Nashville in May, 2012.
2012-13: Jarvinen played 75 games for Nashville AHL affiliate Milwaukee in his first season in North America. He scored 2 goals with 9 assists and was +3. He had 124 penalty minutes, second only to Michael Latta for the Admirals. Milwaukee finished second in the Midwest Division and lost to Texas in a first round playoff series. Jarvinen was -1 with no points and 2 penalty minutes in the four-game series with the Stars.
Jarvinen has optimum size for an NHL defenseman. His biggest challenge will be developing the mobility, speed, and strength to compete at the professional level. A team leader who has captained Finnish junior teams in the past, Jarvinen is a steady, no frills defenseman whose best assets are his positioning and ability to move the puck out of his end or take away shooting and passing lanes. Despite his size and strength, Jarvinen is not particularly intimidating, preferring a more disciplined style of play. He is more of a cerebral player who provides consistency without the flash of some of the more offensive-minded European defenders.
Jarvinen made a stellar transition from Europe to North America and brought with him that big and punishing defensive game he played with at the top level of Finland. As he improves his speed and adjustment to the AHL, Jarvinen could be an outside shot at the Predators lineup in a shutdown role.