Kunitz, a native of Regina, Saskatchewan, has played in 884 career NHL games with the Pittsburgh Penguins, Atlanta Thrashers and Anaheim Ducks, recording 250 goals and 580 points with a plus-183 rating. He won his first Stanley Cup with the Ducks in 2007 before going on to win three more with Pittsburgh in 2009, 2016 and 2017. Kunitz was also named to the NHL's First All-Star Team in 2013.

The 6-foot, 195-pound forward has played in 161 career Stanley Cup Playoff games, making him the Lightning's most experienced playoff performer (Girardi, 122). Kunitz has recorded 27 career postseason goals and 92 points. He has skated in 77 Stanley Cup Playoff games in the previous five seasons.

Kunitz played in 71 games with the Penguins last season, notching nine goals and 29 points. He ranked second on Pittsburgh for hits with 216 while averaging 15:30 in ice time per game. Kuntiz appeared in 20 playoff games, registering two goals and 11 points. He netted the winning goal in Game 7 of the Eastern Conference Final against the Ottawa Senators to send the Penguins to their second consecutive Cup Final.

The 14-season veteran was undrafted out of Ferris State University.