For most of this young season, the Red Sox carried three open spots on their 40-man roster. You knew there was going to be some moves to fix that at some point, whether it be a trade, free agent signing or promotion of player off the 40-man. Teams just don’t waste that kind of space for a long time. When Josh Smith was called up a little more than a week ago, one of those spots was taken. That left them with two, and after today they are left with just the one open spot. On Saturday afternoon Boston claimed minor-league first baseman Joey Curletta off waivers from the Mariners.