Well, his Rdrs as a SS is certainly 13. But as a 2B, he is -9, as a 3B? he is -3, as an OF? he is -1...
As an utility player (overall positions played)?, His Rdsr is -1 through 4 season, so... As an utility player, which is the role that he will assume (not as a SS; you are right at that point) he plays poor defense, below the average.