In his three years with the Winterhawks, Luke scored 130 points in 202 games, improving his points totals in each year. In his final season with Portland in 2009–10, Walker scored a career high 57 points in 61 games, despite missing time due after surgically implanting a plate in his chin after he was hit in the face by a puck on December 8, 2009.[3] He returned to help Portland progress to the second round of the postseason by scoring 10 points in 13 games.
After passing through the draft the two previous years, on June 26, 2010, Luke was chosen by the Colorado Avalanche in the fifth round, 109th overall, of the 2010 NHL Entry Draft.[4][5]
Professional
Walker attended his first Avalanche NHL training camp for the 2010–11 season and after impressing through camp, with eligibility to play in the AHL with affiliate the Lake Erie Monsters, he was signed by Colorado to a three-year entry-level contract on September 28, 2010.[6] Walker remained a constant with the Monsters throughout his entry-level contract with the Avalanche. In his final season with the Monsters, Walker's season was affected by concussion reducing him to 47 games, however still increasing his scoring rate.
On June 24, 2013, with his rights still owned by the Avalanche, Walker signed his first European contract, agreeing to a one-year deal with newly promoted Kontinental Hockey League club, KHL Medveščak Zagreb.[7] On the lower lines of Zagreb and in a checking role, Walker endured a trying season in contributing with just 1 goal in 36 games for the 2013–14 season.
Walker expectedly left Zagreb at season's end and on July 31, 2014, agreed to a one-year contract with Austrian club, Graz 99ers of the EBEL.[8] In the 2014–15 season, Walker quickly adapted to the Austrian league and reached a professional high 19 goals and 31 points in 55 games. After originally re-signing for another season with Graz and after competing in pre-season, Walker and Graz mutually opted to terminate his contract on September 9, 2015.[9] Three days later on September 12, Walker remained in Austria to sign a one-year contract with fellow EBEL club, EC KAC.[10]