McTaggart has a longer article on Roy's injury, complete with quotes.
"On Sunday, he started the game and the rain came, and he went into the cage to finish off his throwing. And a couple of pitches into it, he felt a pinch of some kind in his glute muscle, his rear end. So they've been treating that and he was cleared to go today. At some point today, he felt something on the same side with this hamstring. With the back history and so on and so forth, it makes sense to pop him in there and get him looked at."
"I felt a little tight in the cage, but nothing major. Today, I didn't feel anything. My hammy got tight toward the end. I told them I could go a couple of more innings, but it's Spring Training. It's nothing major. If I need to pitch seven [innings] today, I could have gotten through it."
Not sure if Roy's reference to "the cage" was where he throws on the side, or if that's what he calls his rear end. More later.