With the Detroit Tigers besting the Oakland Athletics last night, the final matchups for both leagues' championship series have officially been set.
However, while all four remaining teams have their overall strengths, there are individuals who can make or break their teams' chances of advancing.
For instance, while the Boston Red Sox are depending on Jon Lester to be a rock, Miguel Cabrera owns a career .526 batting average against him. On the other end of the spectrum, St. Louis Cardinals slugger Carlos Beltran has yet to record a hit against Los Angeles Dodgers closer Kenley Jansen.
Read on to see five matchup nightmares that could cost each MLB team the pennant.