The Yokohama BayStars sent down Alex Ramirez on Thursday with the 38-year-old outfielder hitting a paltry .185 with two homers this season.
It is the first time Ramirez has been demoted due to poor performance since arriving in Japan in 2001.
Ramirez became the first foreign-born player to reach a career 2,000 hits in April, but has struggled badly since, being relegated to pinch-hitting duties for the fourth-place BayStars.
He was hitless in his last 22 at-bats and has not homered since June 2.