The Braves have never wavered on a six-month minimum rehab period for Brian McCann, perhaps making it easier to accept that April 16 is the earliest he could play a major league game. But on a day like Friday, when he took morning batting practice with teammates on the main field for the first time since October shoulder surgery, the itch probably got a little stronger for the six-time All-Star catcher. “I’ve just got to be smart,” said McCann, who also did two sets of 20 throws at 120 feet. “Today was a great day. Throwing was better than it has been, and hitting — today is the best I’ve felt hitting. I’m taking the necessary steps forward.”