Consider the uplink transmission of a single-cell multi-user multiple-input multiple-output (MIMO) system with K single-antenna users and a base station (BS) equipped with a very large number of antennas denoted by M. Consider a jamming device with N > M distributed antennas attempting to deteriorate the communication between the users and the BS. We propose an asymptotic condition on the jamming power under which the jamming-plus-noise subspace overlaps with the signal subspace. Under this condition, existing blind jamming rejection methods, such as the one in [1], fail. The proposed results are based on the application of results from large-dimensional random matrix theory.