An oriented closed connected d-manifold is inﬂexible if it does not admit selfmaps of unbounded degree. In addition, if for every oriented closed connected d-manifold M ′ the set of degrees of maps M′ → M is ﬁnite, then M is said to be strongly inﬂexible. The ﬁrst examples of simply connected inﬂexible manifolds have been constructed by Arkowitz and Lupton using Rational Homotopy Theory. However, it is not known whether simply connected strongly manifolds exist, problem that is related to Gromov’s question on functorial semi-norms on homology. In this talk, using Sullivan models, we present a method that proves the failure of strongly inﬂexibility for all but one of the existing inﬂexible manifolds. This is a joint work with Vicente Mu˜noz and Antonio Viruel.