Well-defined linear segmented block copolymers made of a sequence of hard (T4T diamides) and soft (polytetrahydrofuran) units were melt-processed and characterized theologically by using small amplitude oscillation shear measurements. Increasing the hard-segment (HS) content within the chains from 0 to 5, 10, 15, and 20 wt %HS was found to strongly enhance their plateau modulus, passing respectively from 1.7 to 3.2, 8.5, 13, and 30 MPa. After a brief review of the main models predicting such reinforcement in both homogeneous melts (rubber elasticity) and biphasic materials (hydrodynamics), we propose an alternative view based on a recent work describing the mesoscale structure of our materials. Starting from basic topological arguments, our approach lies on evaluating the volume occupied by a single chain entanglement in the soft phase (V-e) and using it as a reference for counting the number of "stickers" (i.e., HSs) that an equivalent volume in the hard phase would have contained. In this way, the crystallites are seen as local densifications of the polymer network rather than independent fillers providing satisfying predictions up to 15 wt %HS. Our model is then extended to the case of a confined soft phase, i.e., made of non-Gaussian strands, with the aim to describe the modulus upturn generally observed in highly crystalline polymers.