"I can't swing right now," Teixeira told hitting coach Kevin Long. "We need to get this looked at."
An MRI revealed inflammation in the right wrist, and the Yankees placed their first baseman on the disabled list on Tuesday.
Manager Joe Girardi thinks Teixeira will need only a week of rest, but the Yankees decided to put him on the DL so they wouldn't be shorthanded for the games he would miss.
"Inflammation is going to cause some sort of a weakness as time goes on. The more inflamed it gets, the harder it's going to be," Girardi said. "There's not really any hesitation in my mind that makes me believe he won't be back when the 15 days is up."
Teixeira had played in 19 games in 20 days between Class A Advanced Tampa, Double-A Trenton and New York, and he said that could be the cause of the inflammation. He batted .151 with three home runs and 12 RBIs in 15 games with the Yankees.
"Obviously, 19 of 20 is too much. We learned that the hard way," Teixeira said. "If maybe once a week I take a day off -- just to let it rest -- if I can do that all year, that's great."
Teixeira said that he felt great when he came off the DL on May 31, and he showed it, belting three home runs and driving in eight RBIs in his first seven games. But by the middle of the series against the Mariners, he didn't feel like he was finishing his swing from the left side of the plate.
"I changed my mechanics a little too much to protect it, and that's what I didn't want to do," he said. "Once Kevin said, 'Mark, that's not your real swing, you're not finishing your swing.' When your mechanics break down, you stink, and you're hurt. So we've got to fix this."
Teixeira said that his right-handed swing feels fine, but his swing hurts as from the left side of the plate; his right hand is the lead hand. Through 15 games he was batting .278 from the right side of the plate and just .086 from the left.
He has no plans to abandon his left-handed swing, though, not even in the short-term. He said it wouldn't help the team if he only played against lefties, and he has no plans of playing just as a righty rather than switch-hitting.
Right now it's just inflammation, and he has every bit of hope that he'll need only 15 days of rest to get his right wrist back into playing shape. Surgery could still be an option down the road, but he hopes this isn't something that will keep affecting him the rest of the season.
"I'm a positive thinker," he said. "If you're pessimistic in this game, you'll never make it. Because you fail enough, you get hurt enough. If every single day you said, 'This hurts, that hurts and I'm probably going to go 0-fer,' you just wouldn't last. So I'm going to hope for the best."