Any manifold that satisfies this condition must have the property that the complement of a point is an open ball. If we assume that the manifold is complete, then thisThis means that the antipodal set of any point is just a point. Compact symmetric spaces satisfying this condition have been classified by Liu and Deng. See "The antipodal sets of compact symmetric spaces" in Balkan J. Geom. Appl. 19, no. 1, 73-79.