Always looking to improve their offense and defense, the Red Sox add first baseman Mike Carp to their roster.

Getty Images

At first it doesn't seem like a huge upgrade, but Red Sox Manager John Farrell says that the team is looking for a slugger to go against lefties, and Carp has a pretty good average against those pitchers.

For Carp, the Red Sox traded a player to be named later, or a cash option. The Sox moved Ryan Kalish to the 60-day disabled list to make room for him on the roster.