TORONTO — When C.C. Sabathia’s premier fastball abandoned him and years of carrying 300 pounds took its toll on his knees, an overhaul was in order. So he developed a cut fastball and a sinker, put a brace on his balky right knee and became a dedicated student of video, something he never felt he needed to do.
The transformation was not immediate, but Sabathia has proved to be more than a veteran presence in the Yankees’ clubhouse this season. He has buttressed the emerging ace Luis Severino atop the rotation, turning in his best season in five years.