[2][3] During his NHL career, Cooke was criticized and often suspended for hits, some involving head-shots, or knee-on-knee collisions that have injured opposing players.

Most notable was a hit to the head of Marc Savard, which was an important factor influencing NHL rule changes intended to deter such conduct.

[1] Returning to the OHL for a third season after being drafted, he was traded from Windsor to the Kingston Frontenacs on December 17, 1997, in exchange for Brent L'Heureux.

[citation needed] Typically playing in the role of a checking winger, Cooke recorded a career-high 42 points in 2002–03 and earned the Fred J. Hume Award as the team's unsung hero.

[5] Continuing to show offensive capabilities, after returning from an injury in 2003–04, he was promoted to the Canucks' top line towards the end of the season.

On account of Todd Bertuzzi's infamous suspension, Cooke joined Markus Näslund and Brendan Morrison on the Canucks' top line for the final 13 games of the season and the playoffs.

[7] After a year of inactivity on account of the 2004–05 NHL lockout, Cooke would play two more full seasons with the Canucks, scoring at a similar pace.

With Cooke's contract set to expire at the end of the 2007–08 season, he was sent to the Washington Capitals in exchange for Matt Pettinger at the trade deadline.

[citation needed] The next month, Cooke was suspended for two games on January 27, 2009, for a headshot that he delivered to Carolina Hurricanes forward Scott Walker seven days earlier.

Cooke set a new career high during the 2010 Stanley Cup Playoffs by scoring four post-season goals, two of those coming in the decisive Game 6 against the Ottawa Senators at Scotiabank Place.

[12] On June 22, 2010, Cooke signed a three-year contract to stay with the Penguins, a deal worth $1.8 million per season.

In announcing the rule, NHL Commissioner Gary Bettman said, "The elimination of these types of hits should significantly reduce the number of injuries, including concussions, without adversely affecting the level of physicality in the game.

[25] On March 21, Cooke was suspended for the final ten games of the Penguins' regular season schedule, as well as the first round of the 2011 Stanley Cup playoffs, stemming from an elbow to the head of New York Rangers defenceman Ryan McDonagh.

Well into the 2011–12 season, teammate Craig Adams said of Cooke's play, "I've noticed over the last month or so, he's been feeling more comfortable being physical again, obviously, within the rules.

While Senators owner Eugene Melnyk was outraged by the incident, stating, "To have him (Karlsson) taken out by a goon is unconscionable," league officials determined there would be no supplemental discipline for Cooke.

Named to the team with Vancouver Canucks teammate Brendan Morrison, Cooke helped Canada clinch gold, tallying four points in nine games.