I think an important distinction here when we talk about "bulk" is whether Miranda lost fat or muscle or both. It's not like Miranda is suddenly showing up at camp weighing 170 pounds. He's still a big guy, he just lost fat and is in better shape. If anything, that should only help his power. If a 250 pound player lost 60 pounds of muscle and became a distance runner, than yes, I'd worry about his power. But clearly, thats not whats happening here. Whether or not he improves at 3rd base, I think his being in better shape can only help his power and hitting as the season goes on