The Rangers designated right-hander Guillermo Moscoso for assignment on Friday in order to make room for third baseman Adrian Beltre on the 40-man roster.
Moscoso, whose only Major League appearance this past season came in a May 15-28 stint with the big league club, went 7-7 with a 5.18 ERA in 23 games (22 starts) for Triple-A Oklahoma City.
Acquired in a Dec. 8, 2008, trade with the Tigers, Moscoso has a 4.30 ERA in 11 career appearances in the Majors. For his six-year Minor League career, the 27-year-old Venezuelan is 33-22 with a 3.46 ERA.
The Rangers agreed on a six-year, $96 million contract with Beltre on Wednesday.