The Star Tribune of Minneapolis reported the Pirates have agreed to a two-year deal worth $14 million with left-handed pitcher Francisco Liriano.
Liriano, 29, spent 5 1/2 seasons with the Minnesota Twins, who dealt him to the Chicago White Sox for prospects at the trade deadline last season.
Liriano threw a no-hitter in 2011, but has largely struggled the past two seasons, going a combined 15-22 with an ERA over 5.00.
Once a prized prospect for the Twins, Liriano went 12-3 with a 2.16 ERA in 2006. But elbow issues have plagued him since, though has made at least 26 starts in each of the past four seasons.
A power pitcher with a good slider, Liriano owns a 54-56 career record and has 846 strikeouts in 840 innings, including 167 in 156 innings in 2012.
He will be expected to help bolster a rotation that includes right-handers A.J Burnett and James McDonald, and lefty Wandy Rodriguez, all of whom have been acquired via trades by the Pirates.
Liriano is the second major free agent acquisition by the Pirates this offseason, joining catcher Russell Martin, who was signed to a two-year deal worth $17 million late last month.