Right-hander Jeff Karstens was designated for assignment on Friday by the Pirates, who used his vacated roster spot to accommodate newly signed catcher Russell Martin.
Karstens was one of eight arbitration-eligible players affected by Friday's 11:59 p.m. ET deadline for tendering contracts. His DFA status, hence, is a mere technicality, as he will be non-tendered and consequently become a free agent at midnight.
"It was a tough decision," said Pirates general manager Neal Huntington, who was unable to negotiate a fresh deal with the pitcher. "We worked hard to come to a pre-tender agreement with Jeff and his agent and also attempted to work out a trade for him but were unsuccessful.
"We're grateful for what Jeff has done, and wish him well."
The 30-year-old right-hander went 14-13 with an ERA of 3.59 the last two seasons as a regular member of the starting rotation. Karstens was 5-4 during a 2012 season in which he was able to work only 90 2/3 innings between shoulder and hip-flexor injuries.
Acquired from the New York Yankees (along with pitchers Daniel McCutchen and Ross Ohlendorf and outfielder Jose Tabata) in a July 2008 deal for Damaso Marte and Xavier Nady, Karstens compiled a 23-35 record with a 4.31 ERA in five seasons with the Bucs.