"It's a big concern," Yankees manager Joe Girardi said. "He's a huge part of our lineup, and hopefully it's only a couple of days, but we'll find out more tomorrow."
The injury worsened Monday, when Teixeira dove for J.J. Hardy's RBI single and landed on his glove, but the first baseman stayed in the game after assuring Girardi he could play defense. Once the top half of the inning had ended, Teixeira headed into the clubhouse to see if he could swing a bat, but had trouble and exited the game.
Teixeira was wearing a protective brace around his wrist after the game, and he said he'd most likely miss a few days before the injury completely heals.
"I'm not crazy concerned because I tried to play through it," Teixeira said. "It's one of those things where if you really hurt yourself bad, you're out and you can't do much. I was kind of nursing it today when I was swinging, so hopefully it's just a couple days and I can get back out there."
The initial injury occurred on a swing during Teixeira's third at-bat against Red Sox starter Felix Doubront on Sunday. The switch-hitting first baseman was hitting from the right side of the plate, and though he immediately felt sore after the play, he finished the game without a problem. After treatment on Sunday night, Teixeira wore a protective sleeve on Monday and felt he could play through the injury.
Teixeira dealt with a wrist injury in 2009, and after a cortisone shot and a few days of rest, he was fine to play the rest of the year. He's hoping this is a similar injury.
"I popped an oblique before, where you go down and you're out of the game," Teixeira said. "It's something that I tried to play through. More achy and sore than major pain, and that's why I feel OK about it. Hopefully, it's not too bad."
With the team already saddled with injuries to Nick Swisher -- who can handle first base when healthy, but hasn't played the field since mildly straining his left hip flexor on July 20 -- and third baseman Alex Rodriguez, Girardi is short on infielders. Eric Chavez moved from third base to first after Teixeira left the game, and Jayson Nix entered to take Chavez's spot at third.
"It is concerning, but no one is going to feel sorry for us," Girardi said. "We've got guys that are still capable of getting the job done, and that's what you have to do. We've been able to overcome a lot of things up to this point, you just continue to do it."
Ethan Asofsky is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.