Manager Terry Francona said Santana, who exited Monday's game prematurely, felt discomfort in his back prior to Monday's game, but the first baseman insisted on playing through the pain, Jordan Bastian of MLB.com reports.
Francona indicated that he almost scratched Santana from Monday's lineup after the latter experienced muscle spasms while taking pregame swings in the cage. Santana talked his way into the lineup, but the discomfort eventually caught up to him. "On his last at-bat, you could see it was bothering him," said Francona. "Then when he sat down, it kind of grabbed at him."