On November 14th, 2002, the San Francisco Giants traded for Minnesota Twins catcher A.J Pierzynski. In addition, San Francisco gave up pitchers Joe Nathan, Francisco Liriano, and Boof Bonser. The Giants probably would not make this trade if you can go back in time.
At the time of the trade, it probably looked like a good trade because Pierzynski hit .312, with 11 homers and 74 RBIs in 137 games. However, he was also still young, at 26 years of age. In addition, Minnesota had drafted catcher Joe Mauer and Twins were ready to move on from Pierzynski as a catcher.
The Giants would need a catcher because Benito Santiago had filed for free agency and was ready to move on. In Pierzynksi’s lone season with the Giants, he hit .272 with 11 home runs and 77 RBIs. Again, not a bad season, but the issue was that Pierzynski had a problem in the Giants clubhouse. After the 2004 season, San Franciso released Pierzynski, and he signed with the Chicago White Sox.
Nathan had come off an outstanding season for the Giants; he went 12-4 with a 2.96 ERA in 78 appearances. Nathan led all NL relievers in victories. He struck out 83 batters in 79 innings pitched. Nathan went the next season to be the Twins closer and saved 87 games the next two seasons, making the All-Star team both years. The closer pitched 16 years and saved 377 games and six All-Star teams. After playing for the Twins, Nathan pitched the Texas Rangers, Detroit Tigers, and Chicago Cubs before returning to the Giants.
Liriano’s first full season with Minnesota was in 2006, when he went 12-3 with a 2.16 ERA. He struck out 144 batters in 121 innings and made his first and only All-Star team. Liriano started 300 games in his MLB career in 14 years. He struggled his last few seasons with the Twins but pitched better when he went to the Pittsburgh Pirates. With Pittsburgh, Liriano went 46-39 with a 3.65 ERA. In his last season in Pittsburgh, he was a relief pitcher.
Bonser was a top 30 prospect but could not stick in the Twins rotation; Bonser pitched three years with the Twins and went 18-25 with 5.12 ERA. He went on to pitch for the Oakland A’s and Boston Red sox. Bonser’s MLB career ended after the 2010 season.
The Giants gave up two quality young players and a top 30 prospect for a player who only played one year for the Giants. San Francisco thought Pierzynski would be the missing piece, but it did not turn out that way. Instead, they traded away a soon-to-be one of the top closers in baseball and a quality left-handed pitched in Liriano. At the time, Giants general manager Brian Sabean thought it was a good trade.
“While it didn’t come up easy to give up Joe, we feel we’ve got some alternatives within the organization,” San Francisco general manager Brian Sabean said. “It’s not often you can send a right-handed reliever and two unproven prospects for a front-line, All-Star catcher.”