Pedzisa mutsara unotevera: Pakati pemakore ake mana ekuyaruka neTPS mujunior SM-liiga, Niittymäki akasarudzwa neFlyers ye168th yakazara mu
1998 NHL Entry Draft. Akaenderera mberi achitamba muFinland neTPS kwegore rake rekutanga kunze kwemakwikwi ejunior, uye akahwina mukombe weRookie of the Year weFinnish elite league. Mushure memamwe mwaka miviri neTPS, Niittymäki akatamira kuNorth America kunobatana nePhiladelphia Phantoms muAmerican Hockey League (AHL). Apo Phantoms yakakunda AHL Calder Cup championship, akatumidzwa zita rokuti MVP of the playoffs. Akabva atamba mwaka mina yePhiladelphia Flyers asati asaina semunhu akasununguka neTampa Bay Lightning. Gore rimwe gare gare, akasaina semunhu akasununguka neSan Jose Sharks, asi haana kutamba mitambo yakawanda kwavari mumakore maviri akatevera nekuda kwekukuvara kwechiuno. Akatamba mwaka wake wekupedzisira nechikwata chake chevechidiki TPS, uye akazivisa kuti ave pamudyandigere muna 2013.