Something is still amiss with James Harden. The 76ers point guard lacks the explosiveness he displayed while blowing past defenders with the Houston Rockets. It’s the result of the left hamstring tightness that sidelined Harden for most of February. “He’s still not there,” coach Doc Rivers said before Friday’s shootaround at UCLA. “But his miles per hour have increased. He’s … almost to the level of Houston as far as his miles per hour. He’s reached his top speed he hasn’t reached in two years. He’s still a work in progress. But [in] three weeks, we really feel at the time, he’ll be there at 100 percent.”