His injured left wrist, to be more specific.
"The first time was in winter ball in December," Ramirez said, "and in spring training I felt pain again. I was thinking the pain was going to be gone, but it was still there and it got worse."
Ramirez may never know exactly how his left wrist was sprained.
"I was just swinging the bat," he said, "and I got a sharp pain."
Ramirez, ranked 10th among Texas Rangers prospects by Baseball America, came into this season with a .311 career batting average in six minor league seasons.
Largely because of his sore wrist, Ramirez was batting only .238 when he was put on the disabled list May 31.
"I took two weeks to rest, I got a (cortisone) shot and I feel a lot better now," Ramirez said.
The improvement has shown on the field. Ramirez has hit .260 and driven in eight runs in 12 games back from the injury.
He's also been a big plus behind the plate. The RedHawks' pitchers have a 3.86 earned run average with Ramirez catching, but only 4.89 when Emerson Frostad or Kevin Richardson have been the catchers.
Because of the sore catching wrist, Ramirez has been at DH instead of catcher in 25 of the 49 games he's played this season.
"Sometimes," he said. "it hurt just to catch the ball."
At the plate, the biggest change in Ramirez has been how he's cut his strikeout rate in half.
Before going on the DL, Ramirez had struck out in 51 of his 143 at bats, or once every 2.8 at bats. Since returning, he's cut his strikeouts to nine in 50 at bats, or exactly half the previous rate.
"It's all about my wrist," Ramirez said. "When the pain's gone I can swing hard, and now the pain's gone, so I can hit the fastball and everything. I don't strike out so much."
Ramirez hit a game-winning, walk-off home run to right-center last Saturday, his first homer since May 21 and only third of the season.
Hitting cleanup in recent games for the power-shy RedHawks, Ramirez figures to have a dramatic increase in home runs in the second half of the season.
His home run totals have been 21, 16 and 13 the past three years. The RedHawks, as a team, have only 29 home runs through 69 games.
This story was not subject to the approval of the National Association of Professional Baseball Leagues or its clubs.