Mauer, who was officially shut down for the season on Sept. 16, clarified that his illness was related to his upper respiratory infection that caused him to miss two games in Anaheim earlier this month.
"That's how the pneumonia started, and it came to that," Mauer said of having to miss the rest of the season. "That wasn't related to anything else. I tried playing through it and it turned into this, and was just advised by everybody that this isn't the right direction that we're supposed to go. Obviously I was frustrated with it, and obviously I wanted to finish this season playing, but I just wasn't able to."
Mauer said he was diagnosed with pneumonia after a visit to the Mayo Clinic in Rochester, and was relieved to hear there was nothing else wrong with him.
"You think about a lot of things, but you go down to Mayo and they rule a lot of things out," Mauer said. "The thing is, right now I've got to get over this pneumonia, and hopefully I can get over it sooner than later and have a productive offseason."
Mauer knows how important the offseason will be to bounce back next year, as he finishes the season with career lows in batting average (.287), on-base percentage (.369), slugging percentage (.368) and home runs (three) in just 82 games.
Mauer characterized it as a "frustrating" year, as he dealt with various injuries ranging from bilateral leg weakness to a stiff neck and finally his bout with pneumonia.
"You always want to do well when you put the uniform on," Mauer said. "For me, my biggest goal is just to come back and be healthy. It's been a frustrating year. I haven't been healthy. Hopefully, we can do that as a whole. I'm talking about myself, but this whole room, we've kind of got the same thing going [with injuries]. My No. 1 goal is to just get healthy and just get ready for next year."
Mauer, though, wouldn't talk about specific personal goals for next season, but Twins manager Ron Gardenhire said he knows that Mauer always sets lofty expectations considering his past success.
"I think everybody starts the season wanting to have a great year," Gardenhire said. "Joe's a great player. He's been an MVP, an All-Star, a Gold Glove winner, a batting champion. So his expectations are very high. So anything less than a .300 batting average and a chance to be a Gold Glover and a batting champion would not satisfy Joe. Those are his standards. He set them and he tries to live up to them."