SAN DIEGO -- Dodgers ace Clayton Kershaw said the worst part of having a strained teres major muscle is not knowing how long he will be on the disabled list.
"The hard part is not having a set end goal," said Kershaw, who played a gentle game of catch Wednesday to keep his arm loose, without further irritating the muscle that runs from the top of the arm under the arm pit. "Whenever it feels better, I'll go. I tried to play catch to keep the arm going. But pitch in a game? Not sure when that's going to be. That's the hard part."
The reigning National League Cy Young Award winner was scratched from starting Sunday's domestic opener, then hit the shelf when it became clear he wasn't going to bounce back as quickly as hoped.
Kershaw and the Dodgers have not detailed when the injury occurred. He started the first game of the Opening Series in Australia and made 102 pitches over 6 2/3 innings, but he won't pitch again for at least another month.
Manager Don Mattingly stopped short of saying the injuries to Kershaw and teammate Brian Wilson (right elbow) were the result of an abbreviated Spring Training to facilitate the season-opening trip to Australia.
"If I would, I'd be guessing," he said of making the connection. "If you talk to [pitching coach] Rick Honeycutt, if MLB asked him what he thought, he'd have a different plan. He thought it was a little short, that pitchers didn't get on the mound enough. If they listened to Rick, they would have had a different system."
Kershaw said the injury occurred from "throwing hard, obviously. What caused it? At the end of the day, it happened. I try not to think about that. I feel I prepared as well as I could have. I felt great all Spring Training. I don't know what I could have done better. I don't think the flight itself had anything to do with it. Obviously pitching is what hurt it. Whether it was Australia or not, who knows?"
Kershaw said he hasn't taken any injections because he's been told the best prescription is rest.
"I'm not good at that," he said. "Patience isn't a virtue of mine."
Ken Gurnick is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.