The Boston Red Sox had one of the greatest disappointments to close the 2011 season, the classic September collapse that allowed for the Tampa Bay Rays to slip past them in the standings en route to the ALDS. Boston would have to deal with a different disappointment in 2012.
Jacoby Ellsbury, the 2011 runner-up for AL MVP, missed about half of the season to injury, ultimately only playing 74 games. David Ortiz only played 90 games. Bobby Valentine was a failure of a manager in Boston.