Aguero, 26, spent the last five seasons with the Pittsburgh organization, going 11-22 with a 4.14 ERA and seven saves in 103 career minor league games, which include 30 starts. The right-hander, who has never pitched above the Double-A level, has recorded 235 career strikeouts against 101 walks, while opponents have batted .266 during that stretch.
He was added to the Pirates' 40-man roster prior to last season and combined to go 2-5 with a 6.14 ERA and three over 25 relief appearances for High-A Bradenton and Double-A Altoona while also enduring three separate stints on the disabled list.
The Dominican native originally signed with the Pirates as a non-drafted free agent on July 19, 2005. He was designated for assignment by Pittsburgh on March 31 after making a pair of relief appearances in the spring.
To make room on the 40-man roster for Aguero, the club has transferred right-handed pitcher Omar Beltre from the 15- to the 60-day disabled list. Beltre had spine surgery Feb. 23 and opened the year on the Rangers’ 15-day disabled list.
103.3 FM ESPN PODCASTS
Play Podcast Rangers GM Jon Daniels joins Fitzsimmons and Durrett to tackle the tough questions after his team failed to advance to the playoffs.
Play Podcast Nolan Ryan joins Galloway and Company to discuss having Nelson Cruz back in the lineup and how the Rangers are feeling heading into their wild-card play-in game against the Rays.
Play Podcast ESPN Insider and senior MLB analyst Jim Bowden joins Fitzsimmons and Durrett to discuss the wild-card race and the Rangers' chances of making the playoffs.
Play Podcast Chuck Cooperstein joins Ian Fitzsimmons and Tim MacMahon to discuss why he feels Rangers pitcher Yu Darvish isn't an ace.
Play Podcast Elvis Andrus joins Galloway and Company to discuss the Rangers' stretch run and the morale level in their clubhouse.
Play Podcast Nolan Ryan joins Galloway and Company to discuss the latest Rangers news, including the team's struggles, Ron Washington's job security and a rumored trade with the Braves.
Play Podcast Ron Washington joins Ian Fitzsimmons and Tim MacMahon to discuss the Rangers' dismal September, who's to blame for their September struggles and his status as the team's manager.
Play Podcast Fitzsimmons and Durrett discuss how some people are calling for the Rangers to fire manager Ron Washington.