The left-hander will sign a two- year, $14 million contract with the Pirates once he passes a physical.
Liriano reached the majors with the Twins in 2005 and played for them until being dealt to the Chicago White Sox last July. He finished the 2012 season with a combined 6-12 record and a 5.34 earned run average.
With Minnesota Lirano had his best year during an All-Star 2006 season when he was 12-3 with a 2.16 ERA. Unfortunately, that nice season was shortened by a torn elbow ligament and Liriano missed all of 2007.
The Twins had discussed bringing Liriano back, but talks between the parties stalled.
For his career, Liriano is 53-54 with a 4.40 ERA in 168 games (141 starts).
In 2010, Liriano was named the American League's Comeback Player of the Year winner. On May 3, 2011, vs. the White Sox, he threw a no-hitter during a 1-0 victory.