Chavez exited the game in the bottom of the fifth inning, and will undergo head and spine scans at New York Presbyterian Hospital.
The injury occurred in the top of the fifth, when Chavez dove to try to snare a line drive down the left-field line off the bat of the Orioles' J.J. Hardy. Chavez was playing third base in place of Alex Rodriguez, who was the Yankees' designated hitter.
Chavez came up for his at-bat in the bottom of the frame, but facing a 1-2 count, Chavez had to call for time. Manager Joe Girardi came out to check on Chavez, and eventually helped him back to the dugout and toward the clubhouse.
"He came off the field and said he got a little dizzy, but he was all right," Girardi said. "And then when he was going through his at-bat, he got dizzy (again), and when he stepped out, I noticed."
The Yankees were already playing with a short bench on Wednesday night, with outfielder Nick Swisher out because of a strained left hamstring. Swisher is not expected to return to the lineup until early next week, meaning the Yankees will likely have to make a roster move before Thursday's game in Kansas City against the Royals.
"It does limit us," Girardi said about the rash of injuries. "So that's why I feel that at some point we're gonna have to make a move here. I can't tell you exactly what it is, but we're gonna have to do something."
Chavez, 34, was batting .290 with three home runs and five RBIs on the season, his second with the Yankees. He played in just 58 games in 2011, missing almost two months of the season with a broken bone in his left foot that he suffered while running the bases. He hasn't played in more than 90 games in a season since 2006.