[3] In May 1967, Stanfield was traded, along with Phil Esposito and Ken Hodge, to the Boston Bruins, for defenceman Gilles Marotte, centre Pit Martin, and minor league goaltender Jack Norris.

[3] The trade came to be widely regarded as one of the most one-sided deals in hockey history,[3][10][11][12] as Boston immediately became a powerhouse, moving from a last place team to a perennial power.

He was a leading candidate for the Lady Byng Memorial Trophy for the league's most sportsmanlike player, finishing behind eventual winner Jean Ratelle of the New York Rangers and teammate Johnny Bucyk.

[20] Stanfield followed up in the next season, when he scored 20 goals and 58 assists for 78 points, and was named to play in the 1973 All-Star Game as an injury replacement.

Determined to bolster that position, new Boston general manager Harry Sinden traded Stanfield to the Minnesota North Stars for goaltender Gilles Gilbert.

He quickly broke out of his slump, scoring 33 points in 32 games for the Sabres, and contributing to the team's push to the Stanley Cup Finals, where they eventually lost to the Philadelphia Flyers.

His last position in organized hockey was the 1980 season for the Niagara Falls Flyers of the OHA, when he was again named a mid-season replacement as head coach.