The Pirates acquired first baseman Chris McGuiness from Texas in exchange for right-hander Miles Mikolas in a Monday deal involving two players recently designated for assignment.

The Rangers had designated McGuiness on Friday, to make room on their 40-man roster for Shin-Soo Choo. Mikolas had been designated on Dec. 20 by the San Diego Padres, who on Dec. 25 packaged him with outfielder Jaff Decker in a swap with Pittsburgh for first baseman Alex Dickerson.

Mikolas, who ranked third in the Pacific Coast League with 26 saves for Tucson last season, was added to Texas' 40-man roster and will compete with Joakim Soria and Neftali Feliz for the closer's job left vacant with free agent Joe Nathan's departure to Detroit. To open a spot on the roster, the Rangers designated outfielder Rafael Ortega for assignment.

The Bucs thus landed a left-handed-hitting first baseman from Texas -- only, not the one many may have anticipated, Mitch Moreland. McGuiness, 25, is coming off his first Triple-A season, with Round Rock in the Pacific Coast League.

Although he hit only .246 for Round Rock, McGuiness' plate discipline led to an on-base percentage of .369 and an OPS of .792. He also made his Major League debut last season, appearing in 10 mid-June games with the Rangers.

McGuiness was originally selected by Boston in the 13th round of the 2009 First-Year Player Draft before being acquired by the Rangers on July 31, 2010. He was then selected by Cleveland in the Rule 5 Draft on Dec. 6, 2012, before being returned to the Rangers' organization on March 27.

Mikolas had brief stints with the Padres in both 2012 and '13, working a total of 34 innings, yielding 13 earned runs.