Rangers General Manager Jon Daniels said in a statement the 41-year-old, who ranks 14th on the all-time major league home run list with 555 round-trippers, was cut loose from Class AAA Round Rock.
"Based on our evaluation there was not a spot for Manny on the club at this time," Daniels said. "We released him so he could pursue other opportunities."
Ramirez was hoping to catch on with Texas in what was likely a final try to return to the majors following his April 2011 retirement from the Tampa Bay Rays. He left the game at that time rather than serve a 100-game suspension for using performance-enhancing drugs.
It was his second violation of MLB's anti-doping rules.
Ramirez played briefly in the Oakland Athletics' major league system as well as in Taiwan last year before being signed by Texas to a minor-league deal last month.
He connected for three home runs in his first eight games at Round Rock but hasn't homered since, finishing with a .259 average and 13 RBI in 30 games.