Carolina Panthers wide receiver Steve Smith isn’t a doctor, but he seems to be enjoying playing one with his updates on his sprained knee. Smith practiced Wednesday for the first time since injuring his left knee two weeks ago, but it’s still unclear how effective Smith will be Sunday in an NFC playoff game against San Francisco (1:05 p.m., Bank of America Stadium). “Felt good, 71 percent. That’s where I’m at,” Smith said. “I was at 60 (percent) after Monday so today I’m 71.” Smith, the franchise’s all-time receiving leader, was listed as limited on the injury report. Panthers coach Ron Rivera said Smith “was not that limited,” although the team did limit the number of reps Smith took. “You’re always concerned about something coming off an injury, so it’s more of a mental thing than physical. And that’s the part I have to get over, the mental aspect of it,” Smith said. “Physically, I’m fine. But just mentally every day getting better each and every day.” Smith sprained his posterior collateral ligament in the first half against the Saints on Dec. 22, and missed the regular-season finale at Atlanta. The Panthers’ passing game struggled without him.