By Jon Weisman

Considering that Kenley Jansen’s foot surgery took place just before Spring Training began, it had been a relatively quiet time for injuries at Camelback Ranch in the month since pitchers and catchers reported.

Some players on the long road back from injuries, while others including J.P. Howell and Brandon League have been briefly slowed, but nothing of note had affected a starter.

That just changed, with the news, as Ken Gurnick of MLB.com notes, that Hyun-Jin Ryu has received an injection for left shoulder tightness, will be shut down for three days and could start the 2015 regular season on the disabled list.

On September 12, a left shoulder issue that cropped up during a nine-batter, one-inning start at San Francisco sidelined Ryu for 24 days, until he made his return in Game 3 of the National League Division Series. Speaking to reporters in Arizona today, Don Mattingly said Ryu’s current malady was very similar.

“It’d be a pretty safe assumption that this is going to set him back a little bit, and we’re definitely going to be cautious,” Mattingly said.

“I am frustrated,” Ryu said through an interpreter to J.P. Hoornstra of the Daily News. “For this year, I put in a lot of preparation. I’m just going to have to start all over. I’m a little frustrated I got stopped right now.”

It’s still 17 days until Opening Day, so an official decision could be far away and this could all quickly become a forgotten footnote to the preseason. But the Dodgers don’t need a fifth starter until April 14, which is 25 days from now — and in fact, that’s the only day the Dodgers need a fifth starter until April 25. So don’t be surprised if Los Angeles plays it cautiously with Ryu and begins the season with four starting pitchers and an extra reliever amid what has been a spirited competition for spots in the bullpen. (That, of course, assumes the Dodgers’ other four starting pitchers stay healthy.)

Mike Bolsinger, Erik Bedard, Carlos Frias and Joe Wieland are among the starting pitchers in the system that could take Ryu’s place, as well as swingmen including Chad Gaudin and David Huff.