Bean Stringfellow, Wagner’s agent, said Monday that eight clubs have called to express interest in Wagner, a Type A free agent. … Boston, Atlanta, Washington, Houston and Baltimore are on the list, according to Stringfellow, along with three teams that preferred to remain anonymous. … The unnamed teams are probably among the contenders interested in upgrading their late-inning relief: the Tigers, Cubs, Mariners, Rangers, White Sox, Rays and Marlins. …