MLB

Mets ace Santana will see doctor after shoulder ‘discomfort’

Now you can call it a setback.

Johan Santana won’t make his next rehab start in Port St. Lucie tonight or tomorrow, as the Mets had hoped he would. Instead, the lefty will fly back to New York to see a doctor tomorrow at the Hospital for Special Surgery after experiencing “lingering discomfort” in his surgically repaired left shoulder, according to general manager Sandy Alderson.

Santana pitched three scoreless innings for Class-A St. Lucie on Thursday and said he complained of a lack of strength on Monday, but yesterday Alderson said Santana was feeling worse.

He now won’t pitch again until Monday at the earliest, and Alderson admitted this was a setback after yesterday calling it a “tweak in the schedule.”

“It was a day-by-day proposition to see how he came back from his original three innings,” Alderson said. “I think he has less confidence than he might have, so it was prudent to have him checked out. And it will either be reassuring or we’ll step back and see where we are.”

Santana has been on a 30-day rehab stint, but that likely will be reset on Monday after he hasn’t thrown for seven days.

The 32-year-old underwent the same procedure to fix a torn anterior capsule of his throwing shoulder as Chien-Ming Wang did, and Wang just returned to the Nationals after a two-year absence. Using that timeline, the Mets’ hopes of having Santana pitch this year after undergoing the surgery in September was ambitious, but Alderson still won’t rule it out.

“I don’t really believe it’s about this year,” Alderson said. “It’s about a timetable to get him ready. If part of that is pitching games in the major leagues this year, good. If it’s not, it’s not. We’re certainly not gonna rush things. Right now, I think a window in September is open to us. If it closes, that’s the way it goes.”

Alderson said doctors haven’t decided whether Santana will have an MRI exam tomorrow, and the Mets don’t know if the discomfort is due to last week’s start or the long toss Santana did over the weekend. He did not have a bullpen session after the start.

“We anticipated [a setback] into a schedule, and now it’s somewhat longer than anticipated in spring training,” Alderson said of hopes he would be back at Citi Field by June or July. “Right now, it’s a matter of Johan proceeding at his own pace.”

Given the length of time it has taken other pitchers to return to form after similar operations, this hiccup should not be a huge surprise.

“He’s gonna have to be sensitive to how his body responds to an increased workload,” Alderson said. “This is, I wouldn’t say something we expected to happen, but in the overall course of things, it’s probably not something that should be unexpected.”

Particularly not when it comes to the Mets, who have become accustomed to players taking a long time to recover.

“I can’t characterize it as pain versus discomfort versus typical soreness,” Alderson said. “Whatever it is, is sufficient in nature we, and he, want to have it checked.”

And Alderson stressed again the team’s priority is to make sure he’s healthy next season.

“We’re not looking for him to contribute to a pennant race, so we will view September as part of his overall recovery from the surgery,” Alderson said. “If he’s able to pitch, great. If not, we will work that into his offseason schedule and into spring training. But right now, the only thing we’re focused on is him coming up here to get it looked at. Let’s see where goes from there.”

dan.martin@nypost.com