Craig Breslow’s quest to upgrade the Boston Red Sox starting rotation ahead of the July 31 MLB trade deadline could mean a visit to the Steel City. The Pittsburgh Pirates are ready to wheel and deal, with right-hander Mitch Keller being the top trade target. “Keller seems a bit ambitious but isn’t completely out of the question, especially if the return includes a known player they’re reportedly interested in moving,” the Pittsburgh Post-Gazette’s Noah Hiles wrote Wednesday. “If not, (Andrew) Heaney or even a younger, controllable pitcher such as (Mike) Burrows or (Braxton) Ashcraft could make sense.”