Triston Casas first felt the discomfort after a swing against Ben Lively during last Wednesday’s shutout of the Cleveland Guardians at Fenway Park. The Red Sox first baseman thought it was an abdominal issue, but after trying to tough it out for a few days it eventually became clear this wasn’t an injury he could play through. Now Casas is likely to miss several months with what the club described as a rib fracture, though after a series of examinations he likened to an anatomy lesson, Casas explained his injury is actually a bit more complex than a simple bone...