By Stephen M. Cohen Injuries continue to be a story for the Astros down the stretch as Jason Castro and Robbie Grossman were held out of the lineup again Tuesday. Castro sprained his right knee Sept. 2, and then had to have it drained after a cyst was discovered during the MRI. He played Friday and Saturday, but he hasn’t seen the field since. The team is being ultra-conservative with its handling of the All-Star catcher. “We just want to make sure that this is not something that’s going to linger into the offseason,” said manager Bo Porter, “so we’re taking all precautions.” Grossman has been dealing with a strained [...]