Durant suffered the injury late in the second quarter against the Washington Wizards on Tuesday in the Thunder's 125-101 win. After a hard drive to the basket that resulted in a foul, Durant landed awkwardly and immediately grabbed at his left leg.
"After that foul, I came down a little awkward and landed on it a little harder than I wanted to, and it pulled," Durant said after the game.
Durant had an MRI on Wednesday morning that confirmed the strain. Kyle Singler started the second half in place of Durant, but that was only because Dion Waiters was late coming out of the locker room because of "stomach issues," according to coach Billy Donovan.
Durant played in only 27 games last season after having three surgeries to repair a Jones fracture in his right foot.
"Whenever I feel right, whenever I feel ready to play again, that's when I'll play," Durant said. "It was a long process of me getting back, and to get hurt again is unfortunate, but whenever I'm ready to play again, I'll play.
"It's unfortunate, but it's a part of the game. Can't hang my head. Just got to work to get back. I've been here before. It's just a small injury, but I've been here before. I ain't going to quit. I'm not going to give up. I'm not going to be upset. It's just a part of the game."
"Thank God it's nothing too serious for him," first-year coach Billy Donovan said Thursday. "We'll re-evaluate him in seven to 10 days to see where he's at, but for the most part, it's a blessing for Kevin that it's not something that is something really long term for him."
Donovan also stressed that replacing Durant's production will be a team endeavor.
"I think these guys all have a job to do. We're a team. There's going to be different guys that step up at different times. It's not, like I said, one person trying to fill in for Kevin," Donovan said. "Whoever starts in that spot there, it's not his responsibility to be Kevin Durant. Our team needs to make up for whatever it is that we've lost with him being out. I think our guys are going to go out there, and they're going to play, and they're going to do the very best job they can trying to help us as a group evolve and grow and improve in the areas we've got to get better at."
During the next 10 days, the Thunder play five times, against the 76ers, Celtics, Grizzlies, Pelicans and Knicks.
Durant, 27, is averaging 28.1 points, 7.3 rebounds and 3.0 assists in eight games.