Houston Astros catcher Brian McCann will undergo knee surgery, according to Ken Rosenthal of The Athletic. McCann has battled knee issues multiple times over the last season and a half as the veteran is in the back half of his career. He is expected to miss four-to-six weeks and Max Stassi will take over the full-time duties. McCann this season has really struggled, hitting .206 with only eight extra base hits in 155 at-bats. He is slugging only .323 on the season and was hitting .167 over his[...]