Along with sitting out Games 3 and 4, Durant will miss Thursday night's Game 2 at Oracle Arena, Warriors general manager Bob Myers told NBC Sports.
Myers said that the star forward will remain in the Bay Area and rehab with team trainer Rick Celebrini while the Warriors travel to the Moda Center on Saturday and Monday.
Durant originally suffered a right calf strain in the third quarter of Game 5 against the Houston Rockets in the second round. He went up for a jump shot over Rockets defender Iman Shumpert and landed awkwardly.
Durant is averaging 34.2 points, 5.2 rebounds and 4.9 assists per game in the postseason. He has a 51.3 shooting percentage, including a 41.6 percent rate on 3-pointers.
The Warriors hold a 1-0 series lead over the Trail Blazers.