MLB

SANTANA BLISTERS AT HEALTH QUESTIONS

For someone who insists his health is “fine,” Johan Santana sure copped to a long list of previously undisclosed ailments yesterday.

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That can happen when you’ve just absorbed the worst outing of an otherwise illustrious career and the final result is a 15-0 embarrassment at the hands of your crosstown rival.

Acknowledging the mounting concern, the Mets’ ace left-hander admitted to a blister on the middle finger of his pitching hand, a blister on his toe and a sore back all in the past month.

Though all of that might help to explain why Santana has posted a 6.50 ERA in his past six starts, he resolutely refused to make it an excuse for yesterday’s debacle at Yankee Stadium.

“It was a bad day, actually one of the worst of my career, but it’s going to happen,” Santana said after getting torched for a career-high nine runs on nine hits and two walks in three innings.

Santana was peppered with health questions because his velocity has noticeably dropped over the past month, coinciding with the ugly numbers after he posted a 0.78 ERA in his first seven starts.

Santana appeared to top out at 92 mph yesterday, or about 2-3 mph below his usual number, but most fastball readings were in the high 80s. Santana’s usually deadly changeup becomes a lot less deadly when that happens, and the Yankees’ potent lineup teed off on him in a four-run second inning and what became a nine-run fourth.

“What happened is, I made a few mistakes locating my pitches,” Santana said.

Pitching coach Dan Warthen said the various ailments, especially the finger blister, might have caused Santana to unknowingly change his grip on his fastball. The resulting change in angle on the fastball really started to show itself during Santana’s June 2 start in Pittsburgh, a game he lost 3-1, and has been an issue ever since.

“He’s fought through [blister] almost a month, but now that it’s healed, the ball plane has changed,” Warthen said.

“Physically, he’s in good shape. It’s a delivery issue,” manager Jerry Manuel agreed, proclaiming Santana’s recent woes “just a bump in the road” and not the result of medical issues.

“We tend to expect something great every time he goes out there, and in the course of this game, and as long as the season is, you can expect him to have a rough one every now and then,” Manuel said.

Santana said he deserved the benefit of the doubt based on his two-time Cy Young background and bristled at the notion of more serious health issues or “dead arm” that many pitchers go through during a long season.

“Who calls that? You? How you know that?” Santana barked at a reporter who asked him about dead arm. “No, that’s not even close. I’m fine. There’s not much I can say. I’m fine.”

Considering how vital Santana is to their season, the Mets can only hope that’s the case.

bhubbuch@nypost.com