OK, now that we’ve established that Johan Santana might not be ready for Opening Day, the New York Post‘s Bart Hubbach helpfully leans on the lefty and his pitching coach to determine the single most important thing —- who’s fault is it?

Santana threw 31 pitches here this morning before leaving for New York to have his elbow examined by team doctors. Before Santana departed, he repeated his assertion that the aggressive schedule for pitchers mandated by Dan Warthen (above) this spring — bullpen sessions every other day — prompted the injury.

Warthen disputed that after Santana’s bullpen session, saying Santana over-exerted himself because Santana held out false hope of pitching for Venezuela in the World Baseball Classic.

“That’s my speculation, that he had his own quiet agenda, not sharing it with anybody else,” said Warthen, who is in his first full season as the Mets’ pitching coach. “Johan had an inner feeling that he wanted to go represent Venezuela, and I can understand that because he’s the big man down there.”

Santana agreed that he hoped to pitch in the WBC but insisted it was Warthen’s idea — not his own — to throw so frequently.

“Coming into spring training, my mindset was to participate in the WBC,” Santana said. “Somehow, you have to find a way to get ready. At the same time, I was throwing bullpens every other day. I think that’s what it was [that caused the injury]. Too much throwing too soon. Once they said I wasn’t pitching in the WBC, then we back off a little bit. But we were throwing a lot.”