Steve Kerr admitted the calf strain suffered by Kevin Durant is more serious than the Golden State Warriors initially believed.

"Hopefully he continues to progress, and he has made progress but it's a little more serious than we thought at the very beginning," Kerr said. "So we'll see where it all goes, but he's in there all day long getting treatment. He's done a great job of committing himself to that process. [Warriors director of sports medicine and performance] Rick [Celebrini] and his staff are in there all day, and hopefully he'll be back at some point, but we'll just wait and see."

Durant hasn't played since he strained his calf in the third quarter of the Warriors' Game 5 win over the Houston Rockets in the conference semifinals.

Durant won't travel with the Warriors to Portland for Games 3 and 4.

A league source told ESPN's Ramona Shelburne that Durant was "not close" to coming back.

Monte Poole of NBC Sports reported that Durant is likely to miss the entire Western Conference Finals. The Warriors were hopeful of him returning before The Finals, should they advance.