Malkin, 24, who tore his anterior cruciate ligament and medial collateral ligament in a collision during last Friday's game against the Buffalo Sabres, should be ready for the start of training camp, the team said.
The 2009 NHL scoring champion and Conn Smythe Trophy winner as the most valuable player when Pittsburgh won the Stanley Cup in 2009, had 15 goals and 22 assists in 43 games this season.
Malkin, who suffered the injury in his first game back to the lineup after missing five with a sinus infection, is third in team scoring behind captain Sidney Crosby and Kris Letang.
The Penguins, who are three points out of first place in the NHL's Eastern Conference, have been without Crosby for 14 games as he recovers from a concussion. There is no timetable for his return.
(Reporting by Gene Cherry in Salvo, North Carolina; Editing by Frank Pingue in Toronto)