Could be that his calf is still not 100%, but probably a mix of a whole lot of issues like loss of explosiveness due to conditioning, uncertainty of role on team, lack of offensive rhythm, and mental slump following his injury. Not really worried. I'm willing to bet he'd be back to scoring 25+ if LeBron takes a few games off.
As long as LeBron is here we aren’t doing s*** unless his old arse defers completely to the two best players on the team