A second-round (47th overall) selection of the Kings in the 2010 NHL Entry Draft, Toffoli will be entering his sixth NHL season in 2017-18. He has appeared in 293 regular-season games posting 175 points (84-91=175), a plus-90 rating and 91 penalty minutes. His plus-90 rating ranks third on the Kings all-time list, and first among active players.

Toffoli was a part of both Stanley Cup winning teams. Overall he has appeared in a total of 43 playoff games with Los Angeles, recording 21 points (9-12=21), a plus-6 rating and 12 penalty minutes. During the 2014 Stanley Cup run he ranked first among all rookies in goals (7), points (14) and game-winning goals (2).

He posted career-highs during the 2015-16 season in goals (31), assists (27), points (58) and games played (82) while also leading the league with a plus-35 rating. He was the first King to break the 30-goal mark since Anze Kopitar did so in 2009-10.