The 29-year-old Liriano has had just one season in which he has made at least 30 starts since he came onto the scene in 2005. The last two seasons his earned run average has been over 5.00 and his walks and hits per inning pitched is over 1.450.
The Pirates are reportedly continuing talks with the Liriano camp trying to negotiate new terms.
General manager Neal Huntington said the club continues "to have dialogue with Francisco's representatives, but there is nothing to announce at this time."
The Pirates were hoping to plug Liriano into the rotation behind A.J. Burnett and lefty Wandy Rodriguez.
Liriano went 6-12 in 2012, splitting the season between the Twins and the White Sox.