Goaltender Harry "Hap" Holmes and forward Frank Foyston were his teammates on all three Stanley Cup winning teams.

Carpenter and Walker each scored a goal, but the Port Arthur team lost 4-13 in front of 3,000 spectators at the Laurier Avenue Arena in Ottawa.

[4] For the 1911–12 season future Hockey Hall of Fame members Harry Cameron and Frank Nighbor joined the Port Arthur team from Pembroke, Ontario, but after the team defeated the Saskatoon Wholesalers 12-6 (11-1, 1-5) in a qualifying two-game series on March 2 and 4, 1912 for a chance to challenge the National Hockey Association champions (Quebec Bulldogs) for the Stanley Cup, Port Arthur nonetheless turned down the opportunity because they felt they had practically no chance to defeat the NHA champions.

The Blueshirts then defeated the Victoria Aristocrats, champions of the Pacific Coast Hockey Association (PCHA), in three straight games 5-2, 6-5 and 2-1 between March 14 to 19.

The Patricks raided the Blueshirts and created a new PCHA team in the Seattle Metropolitans, stocking it with Walker, Eddie Carpenter, Harry "Hap" Holmes, Frank Foyston and Carol "Cully" Wilson.

[8] In his second season with the Metropolitans, in 1916–17, Walker helped the American team to a first place finish in the PCHA, in front of the Vancouver Millionaires, Portland Rosebuds and Spokane Canaries.

World War I had a big impact on the game, and prior to the 1917–18 season Walker and Eddie Carpenter were stuck in Port Arthur working on a dry dock.

The Cougars, led offensively by their Icelandic-Canadian star forward Frank Fredrickson, only finished third in the 1924–25 WCHL standings, but they succeeded in winning the following league playoffs (defeating both the Saskatoon Crescents and the Calgary Tigers) which gave them the opportunity to play NHL champion Montreal Canadiens for the Stanley Cup.

Walker, who had a modest regular season offensively speaking with the Cougars, turned it on for the playoffs, scoring 4 goals during the WCHL playoffs and 4 goals in the Stanley Cup finals, helping the Cougars defeat the Canadiens 3 games to 1 while being matched against the Canadiens young star forward Howie Morenz.

[19] In a 1960 interview with Bill Westwick of the Ottawa Journal, Nighbor claimed he had learned his famous poke checking technique by watching Walker while the two players were teammates in Port Arthur.

One serious injury he did suffer happened during the 1921–22 season when he was hit over his already injured left hand in a game in Victoria on February 10 and blood-poisoning set in to the wound.

Lester Patrick, the hockey mogul behind the PCHA and later a two-time Stanley Cup winning coach with the New York Rangers, had high praise for Walker, calling him "one of the greatest players who ever lived" in a 1950 Maclean's magazine interview, but he also stated that in comparison with contemporary players like Cyclone Taylor, Frank Nighbor, Howie Morenz, Eddie Shore, Moose Johnson, Ching Johnson and Frank Fredrickson, Walker, much like his Seattle Metropolitans teammate Frank Foyston, "lacked color" and "no matter how brilliant he was, he didn't bring the crowd to their feet.