The Red Wings were in last place of the NHL's East Division late in the 1967–68 season when, on March 3, 1968, they completed one of the biggest trades in league history up to that time: Henderson was sent to the Toronto Maple Leafs as part of a six-player deal, along with Norm Ullman and Floyd Smith, in exchange for Frank Mahovlich, Garry Unger and Pete Stemkowski. Henderson finished the season with 11 points in 13 games for Toronto, then scored 27 goals and 59 points in 1968–69.