No. 4 LA Angels move that did not work out as planned: Vernon Wells trade (2011)
Vernon Wells was a total bust for the LA Angels. Wells was acquired via trade with the Toronto Blue Jays so we at least didn't have to pay ALL of his seven-year/$126 million contract. We took on the last four, however, and he only played two with us.
And he was legitimately awful with us. He hit .222/.258/.409 (.667 OPS) in just 208 games, and totaled just 36 home runs, 95 RBIs, and 96 runs. We ended up having to pay most of his contract in his year with the Yankees after he played two seasons with us too.
It was a very horrible situation for us, and he didn't even finish the contract in the Big Leagues, but on the couch. His playing career finished after the 2013 season. Wells also didn't play the defense he did back in his prime.
We traded Juan Rivera and Mike Napoli for him. In Napoli's two years with the Rangers (until he returned later in his career), he hit .275/.379/.552 (.931 OPS) and was an All-Star in the second year (2012). He became very good very quickly, and we were stuck with Wells.