  We introduce the notion of potentially klt pairs for normal projective
varieties with pseudoeffective anticanonical divisor. The potentially non-klt
locus is a subset of $X$ which is birationally transformed precisely into the
non-klt locus on a $-K_X$-minimal model of $X$. We prove basic properties of
potentially non-klt locus in comparison with those of classical non-klt locus.
As applications, we give a new characterization of varieties of Fano type, and
we also improve results on the rational connectedness of uniruled varieties
with pseudoeffective anticanonical divisor.
