NEW YORK -- Johan Santana is done for the year, and to say he had an up-and-down season would be an understatement of Cy Young proportions.
Explaining that their struggling ace is worn down from two years of rehabilitation and near-constant maintenance, the New York Mets placed Santana on the 15-day disabled list Wednesday with inflammation in his lower back and said he is not expected to pitch again in 2012.
Doctors recommended rest, but not surgery.
"I wanted to keep pitching. I felt that I could pitch. But at the same time, I'm listening to them," Santana said. "They said that everything that I have done has been a lot. At some point I have to take some rest. At this point I think I agree with everything and we've just got to make sure we stay healthy and look forward to next year."
The 33-year-old Santana missed last season following major shoulder surgery in September 2010 to repair a torn anterior capsule. He got off to a strong start this year and pitched the first no-hitter in Mets history June 1 against St. Louis. But he threw a career-high 134 pitches in that game and is 3-7 with an 8.27 ERA since.
"I don't have any second thoughts about the way it was handled," general manager Sandy Alderson said. "This has not been a shoulder issue. So from that standpoint, I just don't see a direct correlation."
The tailspin got ugly after Chicago Cubs outfielder Reed Johnson stepped on Santana's foot on a play at first base July 6. Beginning with that outing, Santana went 0-5 with a 15.63 ERA in his final five appearances -- becoming the first Mets pitcher to give up at least six runs in five consecutive starts.
The two-time AL Cy Young Award winner was 6-4 with a 2.76 ERA through June but ended up 6-9 with a 4.85 ERA. He threw 117 innings in 21 starts.
"At this point I'm very confident he'll be back next season and ready to go and hopefully in a stronger position than he was coming into this year," Alderson said. "If you look back at the season and what we reasonably could have expected at the beginning of the year, he's actually accomplished quite a lot. I think as we got close to midseason we recognized that, who knows how long Johan can go?
"I can't sit here and say this is a shock or even a surprise. It's disappointing, but that's the nature of things," the GM added. "I don't believe that fewer innings would have preserved Johan. ... I don't think he was overused. There were times when he had extra rest."
A few weeks after Johnson stepped on his foot, Santana was placed on the DL with a sprained right ankle. He was sidelined for three weeks, a stint that was also intended to recharge his surgically repaired shoulder.
But in his first game back, Santana lasted only 1 1-3 innings against Atlanta -- the worst start of his career. He said Wednesday that he's been feeling tightness in his back for a couple of weeks, but it really stiffened up on him in his most recent outing last Friday at Washington.
"The work he did to try to command stuff, the absolute effort he had to put in to make each pitch, wore him down. And so, that was obvious. And you just knew that some adjustments had to be made," manager Terry Collins said. "I think the rest is the perfect medicine for him right now."
Santana had an MRI on Tuesday that revealed the inflammation and the left-hander was prescribed rest, medication and intermittent exercise.
"There is no issue with his ankle, no issue with his shoulder," Alderson said. "Obviously, with a back problem and continuing to pitch, that itself could lead to problems with the shoulder or the ankle or an elbow, and that's another reason why we're trying to be cautious about this."
Santana was placed on the DL retroactive to Saturday and New York will bring up right-hander Collin McHugh from the minors to start in his place Thursday against Colorado.
So now, Santana will look toward 2013, the final guaranteed season of his $137.5 million, six-year contract.
"I'm very positive that everything's going to be fine," he said. "It's too bad that I have to go down like this, but it's part of the game."
The slumping Mets began the night 57-66. Santana said he will stay with the team through the end of the current homestand but after that, he's not sure. Alderson said he thinks Santana will want to head home to Florida to rest and then begin his off-season program.
"He's healthy. All right, he's got a tweak in his back. With rest and his exercises, it'll go away. There's no reason to expect that next spring we don't have anything but probably the best condition he'll be in in a long time, with some rest and recuperation," Collins said. "He's looking at the season as a positive. I think we're in a good spot going into the winter.
"It's time for a rest. But, when that rest is up, that rest is going to be over next February. And it's time to get after it."
The Mets had recently committed to a six-man rotation with the intention of giving Santana and Chris Young extra rest, but Collins said they might go back to a five-man cycle now.
The 25-year-old McHugh hopes to have his wife and parents in attendance for his big league debut Thursday.
"It'll be fun," he said.
NOTES: Alderson said OF Kirk Nieuwenhuis, demoted to Triple-A Buffalo on July 29, is expected to miss the rest of the season with a partially torn plantar fascia.