One day after the Twins announced Tsuyoshi Nishioka had been shut down for the final two weeks of the regular season, the Japanese infielder said his first year in Major League Baseball has been one big learning experience.

Unfortunately for Nishioka, most of the lessons he has learned have been hard ones.

"It has been a season in which everything has gone wrong," he said through his interpreter Saturday. "In a long life [everyone] has one like this, and I think 2011 was a year in which everything went the other way."

In recent weeks, Nishioka tried to play through a strained right oblique muscle, with little success. So the Twins decided to keep him off the field so he can recover properly and begin an offseason program to prepare him for what likely will be a make-or-break year in 2012.

As soon as he recovers from his injury, Nishioka plans to jump right into training for next season -- a change from how he usually approaches his offseasons.

"In Japan, the season ends pretty much about the same time [as MLB] and I usually take October, November and December off from baseball activities," Nishioka said. "But this year I'm hoping to get back and practice from October. I think that's why I'm preparing for the offseason now and the start of training."

Nishioka was shut down the same day as catcher Joe Mauer, who has been diagnosed with mild pneumonia and ordered to stay home. There's a good chance they will be joined by first baseman Justin Morneau, who can't shake concussion symptoms and also is battling a stomach virus. Morneau wasn't at Target Field on Saturday, either.

And outfielder Jason Kubel's season is in jeopardy because his bruised left foot has bothered him more in recent days. For these Twins players, the chance to try to finish the regular season on a positive note is gone. Kubel has appeared in only 99 games. Mauer, Morneau and Nishioka each will miss at least 70 games because of injuries.

Manager Ron Gardenhire said that Perry Castellano, the Twins' strength and conditioning coordinator, has designed an offseason program for Nishioka to help him report for spring training next season in the best shape possible.

"His upper body is not as strong as I think it can be," Gardenhire said. "He can gain upper-body strength, and that is going to help him with his swing. Perry has a good program written up for him, and I know Nishioka [already] has a good program over there."

Will that be enough to turn Nishioka into a major league-caliber shortstop? He batted .226 with 19 RBI and two stolen bases in six attempts. He was charged with 12 errors and failed to make many other plays.

He missed 59 games because of a broken leg suffered on April 7 in New York. Gardenhire said Nishioka never regained the speed he had before the injury. Nishioka was a mess at the plate most of the season, and he was just starting to have success with some of the adjustments he made with the help of hitting coach Joe Vavra when he came down with the oblique injury.

"He never got into the flow of playing games," Gardenhire said.

As the season winds down, the Twins simply don't know what they have in Nishioka, a Japanese batting champion in 2010 in whom the Twins invested $14.55 million to bring over on a three-year contract. It will be up to him to come back a better player in 2012. There will be an open competition for the starting shortstop job next season, and Nishioka could find himself on the bench -- or in the minors -- if he doesn't make a quantum leap.

"I think that not putting up the numbers doesn't mean I didn't give 100 percent," Nishioka said. "So next year I hope to give it all as I did this year and make it a better year."