The Warriors announced that Durant is out indefinitely and would be re-evaluated in four weeks.
Golden State said Durant could play again in the regular season. The Warriors' final regular-season game is scheduled for six weeks from Wednesday's announcement.
"At this time it's just speculation to guess when that is," general manager Bob Myers said in a conference call. "He'll heal as his body heals. And when he's healed and our doctors clear him and we feel like it's safe, he'll play. I want to know as much as you guys, but at this point the plan is just to re-evaluate him and see where he's at in four weeks."
Myers acknowledged a 10- to 15-minute window in which the Warriors thought Durant's injury was season-ending.
"There was a moment where there was a potential different diagnosis," Myers said, "but that didn't last too long and most of it was let's get another image to make sure we have a clear look at this, and that's what determined the final diagnosis as I was told."
Warriors forward Draymond Green told The Undefeated's Marc J. Spears in a text that he is "relieved" by the diagnosis.
"I'm definitely relieved. I thought it would be way worse," Green wrote. "Being away weeks sucks, but we will take that over what was initially thought."
Durant suffered the injury in the first quarter of Tuesday night's 112-108 loss to the Washington Wizards. The injury occurred during a loose-ball situation in which Wizards center Marcin Gortat fouled Warriors center Zaza Pachulia, who then fell backward into Durant's leg. Durant jumped away from Pachulia's contact, hopping while holding his left leg.
He proceeded to play the next two possessions before asking Warriors coach Steve Kerr to call timeout with 10:26 remaining in the quarter. After meeting with trainers, Durant, who was grimacing and holding his left leg, headed to the locker room and did not return.
Durant underwent an MRI on Tuesday night that revealed a Grade 2, or moderate, sprain in the knee and a bruised tibia.
Durant is in "good spirits" given the initial fears about the severity of the situation, league sources told ESPN's Marc Stein.
Sources told Stein and ESPN's Ramona Shelburne that Durant, who will soon return to the Bay Area to begin treatment and recovery, was initially told he had suffered a fractured tibia as opposed to a bruised tibia, which would have been season-ending.
Nobody on the Warriors felt any concern that the play was intentional, Myers said.
"These things happen in sports," he said. "Nobody's raised that question on our side. I don't know if it's being raised outside of us. I spoke to Kevin a couple times. Other than just being disappointed that he's injured, nobody's mentioned anything like that."
Wednesday's injury news could challenge the Warriors (50-11) in their effort to clinch home-court advantage throughout the playoffs for the third straight season. After Thursday's 94-87 loss to the Chicago Bulls, they lead the San Antonio Spurs (46-13) by three games for the West's top spot.
The Warriors remain the outright favorite to win the NBA title at the Westgate Las Vegas SuperBook, with oddsmakers dropping Golden State slightly from minus-220 to minus-200 to win their second title in three years after Durant's injury status was announced.
In the wake of Durant's injury, the Warriors agreed to a deal with veteran swingman Matt Barnes, he confirmed to ESPN. The Sacramento Kings waived Barnes on Feb. 20 because they needed a roster spot to accommodate the players they received in their DeMarcus Cousins trade with the New Orleans Pelicans.
Information from ESPN's David Purdum and The Associated Press contributed to this report.