ARLINGTON -- Astros catcher Jason Castro felt good enough to play Wednesday night, but manager Bo Porter kept him out of the starting lineup against the Rangers for a third consecutive game after he came down Sunday night with an undiagnosed pain in his left armpit.
While Castro doesn't know the cause of the pain, it has subsided with medication and rest. He said he could have played, and Porter said he could be used Wednesday in a pinch-hit situation.
"I feel a lot better today," Castro said. "The treatments and the anti-inflammatories have really been doing what they're supposed to, so it looks like hopefully it's behind us and I'm going to hit on the field today. I hit in the cage already and it even felt better than it did [Tuesday]. I'm pretty happy about that and should be fine moving forward."
Castro was hitting .462 (6-for-13) in three games prior to the injury after getting moved into the No. 2 spot in the batting order. Porter said since the team is scheduled to have a day off on Thursday, there was no use rushing Castro back too soon.
"We don't want there to be anything that would be a concern moving forward," he said. "Could he play today? He could probably play. Would he be pain free? Probably not. We'll take today and with the off-day tomorrow and the progress he's made, by Friday it will be completely behind us."
As for what caused the pain, Castro still isn't sure.
"Unless I was to get a blood test, I don't think they have a definitive answer," Castro said. "I think the best guess is that it was some kind of irritation with the lymph node. It wasn't swollen, necessarily. They couldn't find any swollen nodes in there, but some kind of irritation with it, and that's what was causing the pain."
Brian McTaggart is a reporter for MLB.com and writes an MLBlog, Tag's Lines. Follow @brianmctaggart on Twitter. This story was not subject to the approval of Major League Baseball or its clubs.