Niinamaa was a nimble and agile players. His wide stance allowed for great power and balance. He was a dynamic skater but his puckhandling ability matched that. He read offensive plays expertly, making him an excellent powerplay quarterback. Defensively the left-shooting defenseman played the right side with proficiency. He was far from aggressive but he handle a lot of minutes and never backed down from a one on one battle.
Niinimaa was a 1993 second-round pick (36th overall) of the Philadelphia Flyers but he opted to play three additional seasons with Jokerit in his native Finland before jumping to the NHL in the 1996-97 season. He made an immediate impact with 44 points in 77 games. He really made a strong impression with his poised play as the Flyers advanced to the Stanley Cup final. In fact, he led all players with 12 assists in 19 games.
Early in his career Niinimaa was criticized a bit for being too active and taking too many gambles, which likely led to his trade to the Edmonton Oilers midway through the following season. He spent six seasons out west where I was better able to appreciate his steady if unspectacular play. He learned to be more patient and let the game to come to him rather than trying to create plays that just were not available. He really matured into solid player in Edmonton.
Niinimaa rounded out his NHL career with vagabond stops with the New York Islanders, Dallas Stars and Montreal Canadiens. He returned to Europe playing in Switzerland and Sweden for several more seasons after exiting the NHL
In 741 NHL games Niinimaa had 54 goals and 319 points. He also had 24 points in 59 Stanley Cup Playoff games.
Internationally Niinimaa won a bronze medal with Finland at the 1998 Nagano Olympics and a gold medal with Finland at the 1995 IIHF World Championship. He also won Finnish league titles with Jokerit in 1993-94 and Karpat in 2004-05, and a Swedish league title in 2009-10 with HV71.