Armia's contract has an average annual value of $2.6 million, while Lehkonen's has an average of $2.4 million.
Armia, 26, set career highs for goals (13), power-play goals (two) and power-play points (six) in his first year with the Canadiens this past season. He also added 10 assists. Armia has 39 goals and 42 assists in 237 career NHL games for the Buffalo Sabres, Winnipeg Jets and Canadiens.
Lehkonen, 24, appeared in all 82 games for the Canadiens last season, setting career highs in assists (20), points (31), game-winning goals (four), shots (176) and differential (plus-10). He has 41 goals and 30 assists in 221 career games, all with Montreal.