Nokelainen played for the junior teams of Ketterä until the age of fifteen, when he moved to play for the elite league organization, SaiPa, in the neighboring town. He has always been a regular for the junior national teams and played his first two professional games at the end of the 2002-03 season, scoring his first goal in the latter. SaiPa struggled mightily in Nokelainen’s draft year. His linemates changed constantly in the second and third lines, but he remained, going back to juniors only on occasion to help the team. He also made the WJC team, where a notable defensive role was unique to a Finnish forward of his age.
Drafted by the New York Islanders in the first round of the 2004 NHL Draft, 16th overall.
2006-07: Things did not go as well as planned during Petteri Nokelainen’s debut season with the Sound Tigers. He got off to a slow start following off-season knee surgery for patella tendonitis and the coaching staff felt it best to give him a game off here and there to rest the knee and get it back to shape. This resulted in his not having recorded his first professional point until November and his first professional goal until December. Nevertheless, Nokelainen played through it all, that is, until he suffered a broken finger that caused him to miss out on an additional 14 games. All in all, the right winger played in 60 games, totaling six goals, 10 assists and 16 points, finishing -11 and with 51 penalty minutes.
2008-09: Traded to the Anaheim Ducks in the deal that sent Steve Montador to the Boston Bruins.
Nokelainen's ability to play two-way hockey can't be stressed enough as that is what makes his game. He positions himself well to always be where he is needed, whether that is starting an odd man rush or wrestling in the corners of the offensive zone. Needless to say, he is a top choice to kill a penalty. However, his offensive skills are average all around. He does score quite a lot against his peers and his willingness to use the slapshot is a good sign of confidence, he may not have what it takes to match the numbers of the best defensive forwards in the game. The largest question mark is his speed, which is mediocre for a player of his quality, yet he still seems to improve. Nokelainen may not get a lot of press before draft day, but he looks to be favored by coaches over many other players.