Evgeni Malkin had surgery on his left elbow and the Pittsburgh Penguins forward is expected to recover in 3-4 weeks.
Penguins forward Zach Aston-Reese had surgery on his left shoulder and will need six months to recover.
A start date for next NHL season has not been announced.
Malkin had one assist and a Pittsburgh-leading 21 shots on goal for the Penguins, the No. 5 seed in the Eastern Conference, in their four-game loss to the Montreal Canadiens, the No. 12 seed, in the Stanley Cup Qualifiers. He led the Penguins with 74 points (25 goals, 49 assists) and was plus-7 in 55 games during the regular season.
The 34-year-old has missed at least 10 games in seven of his past eight seasons. He has averaged more than a point per game in 13 of his 14 NHL seasons and has 1,076 points (416 goals, 660 assists) in 907 NHL games.
Malkin is a three-time Stanley Cup champion with the Penguins (2009, 2016, 2017) and was voted winner of the Conn Smythe Trophy as most valuable player in the Stanley Cup Playoffs in 2009. He won the Art Ross Trophy as the top scorer in the NHL in 2008-09 and 2011-12, was voted winner of the Hart Trophy as League MVP and the Ted Lindsay Award (most outstanding player as voted by members of the NHL Players’ Association) in 2011-12, and was voted winner of the Calder Trophy as the top rookie in the NHL in 2006-07.
Aston-Reese scored 13 points (six goals, seven assists) in 57 games this season, and had one assist in the Cup Qualifiers. The 26-year-old has 36 points (18 goals, 18 assists) in 116 games over three seasons with Pittsburgh.