LOS ANGELES -- Don Mattingly seemed to get a little tense the other day when asked to explain the difference between Matt Kemp's struggles in center field and Hanley Ramirez's struggles at shortstop, and why one led to a position switch and the other has not.Kemp was asked to turn to his left and keep walking until he found a position where he could do less damage. Why shouldn't Ramirez be as well?If anything, Ramirez is the bigger liability than Kemp.