The 29-year-old defenseman, who was an unrestricted free agent, scored 23 points (five goals, 18 assists) in 47 games for the Devils last season before being traded to the Carolina Hurricanes on Feb. 24. Vatanen did not play a game with the Hurricanes in the regular season because of a lower-body injury, but he returned for the Stanley Cup Playoffs and had three assists in seven games.
"[Vatanen's] highly competitive. Another veteran guy that we can put inside our dressing room that knows how to play the game the right way," Devils coach Lindy Ruff said. "Competes at a very high level, great teammate, just another good NHL defenseman for us. So it's a real good acquisition. I think we have some real good young players that are progressing. At the same time, if we can bring a Sami in and he plays well for us, it should make us a better team."
Selected by the Anaheim Ducks in the fourth round (No. 106) of the 2009 NHL Draft, Vatanen has scored 194 points (45 goals, 149 assists) in 434 regular-season games for the Devils and Ducks, and 26 points (six goals, 20 assists) in 51 playoff games.