Ainge and the Celts have no choice but to put one foot in front of the other and move forward. “I try to get outside,” he said over the phone as he took in the fresh air. “The weather’s been pretty good. But I’ve been going into the office. I’ve been the only one that’s at the facility, and mostly just watching film and walking inclines on the treadmill and walking the back stairway and doing some exercise.”