Bard was limited to 57 games because of injuries. He sprained his left ankle when Albert Pujols slid into him at home plate on May 21, sidelining him until late July. He also was sidelined in August with a strained right triceps.
Bard hit .202 with one homer and 16 RBIs. He played in parts of three seasons with San Diego.
The 35-year-old Estes, who didn't pitch in the majors in 2007 while rehabbing from reconstructive elbow surgery, began the season at Triple-A Portland before his contract was purchased by the Padres on May 8. He was 2-3 with a 4.74 ERA in nine appearances, including eight starts. Estes was sidelined for more than two months with a broken left thumb.
Hayhurst, 27, made his big league debut with the Padres on Aug. 23. He was 0-2 with a 9.72 ERA in 10 games, including three starts. Carlin, 27, had three stints with the Padres, making his big league debut on May 10. Kazmar, 24, made his major league debut with the Padres on Aug. 13.
The Padres, meanwhile, are pursuing a grievance against shortstop Khalil Greene for breaking his left hand when he punched a storage chest out of frustration.
The Padres are trying to recoup a prorated portion of Greene's $4.5 million salary. He missed the final 52 games.
Greene hurt himself on July 30 after fouling a ball off his shin before striking out for the 100th time.