Don Mattingly wouldn’t say so directly — he treats injury timetables like state secrets these days — but the next few days are critically important for Clayton Kershaw.

First, the good news: Kershaw played catch Friday at Dodger Stadium for the first time since an MRI of his left upper back Wednesday showed inflammation of the teres major muscle. Kershaw didn’t speak to reporters, but Mattingly filled in the details of his conversation with the pitcher.

“I think in his mind that went really well,” Mattingly said. “He said he didn’t feel anything throwing. He wasn’t trying to throw 95 (mph) or anything. My next question was, ‘did you feel anything the other day?’ and he said ‘yes.’ That tells us he’s taken a little step forward. That doesn’t mean a whole lot at this point, but that means we continue on with the process moving forward. He’ll throw again tomorrow with a little more intensity and we’ll see how that goes.”

There’s no need for Kershaw to rush back. The Dodgers have off-days Monday and Thursday as regular-season play resumes next week. If the Dodgers are intent on using five starters from the outset, they won’t need a fifth starter until next Saturday’s game against the San Francisco Giants.

Mattingly wouldn’t say if starting that game is a possibility for Kershaw.

“He still has to get past these next two days,” Mattingly said. “I’m sure every day is going to be a little bit of a barrier to cross. The one thing we can keep in mind, from our standpoint and from a medical standpoint, from the top of this building from the top office, (with) Clayton, we’re not going to let him go out there unless he’s 100 percent. If there’s any doubt that he’s 100 percent, we’re going to hold him back.”

If he can’t pitch a week from now, it’s possible if not likely that Kershaw would go on the disabled list for the first time in his career. Since he hasn’t pitched since Opening Day in Sydney, Kershaw could be placed on the DL retroactive to March 23. That would make him eligible to rejoin the active roster April 7. That’s an off-day for the Dodgers, followed by a pair of home games against the Detroit Tigers.

Therein lies the bad news: The Dodgers could place Kershaw on the DL and he would be unavailable for only six games. The option suddenly makes a lot of sense.

The only way it doesn’t make sense is if Kershaw makes enough progress in the next couple days to be ready sooner.

Kershaw was scratched from his scheduled start Sunday in San Diego. Left-hander Hyun-Jin Ryu is tentatively expected to start that game.