Sometimes, offseason acquisitions work out. Sometimes they don't. Sometimes, they are spectacular failures.
Jeremy Giambi was acquired in December 2002 by Theo Epstein as part of the overhaul of the Red Sox lineup. Giambi was a high-on-base percentage player and was expected to be the starting designated hitter in the new-look offense.
Unfortunately, things did not work out. Giambi was frequently injured and struggled when he was in the lineup. He stuck around through the entire year, but only played in 50 games. Giambi, the younger brother of then-Yankee Jason Giambi, only hit .197/.342/.354/.696 with five home runs. This, a year after hitting 20 home runs.
His on-base percentage was decent enough, considering he rarely got a hit, but he was a big bust otherwise. Giambi lost his job to David Ortiz, who of course became a huge star with the Red Sox.