The layered perovskite ${\mathrm{La}}_{3}{\mathrm{Ni}}_{2}{\mathrm{O}}_{7}$ has attracted a great deal of attention recently due to the observation of unconventional superconductivity $({T}_{c}\ensuremath{\approx}80\phantom{\rule{0.16em}{0ex}}\mathrm{K}$) at high pressures. Motivated thereby, we present a computational study based on density functional plus dynamical mean-field theory calculations for the normal-state electronic reconstruction of a pressurized ${\mathrm{La}}_{3}{\mathrm{Ni}}_{2}{\mathrm{O}}_{7}$ superconductor. We show how a coherence-incoherence crossover behavior manifests itself due to sizable electron correlation effects in the ${e}_{g}$-shell one-particle spectral functions. Our results capture the $T$ dependence of the resistance, providing a many-particle interpretation for the emergent strange metal behavior seen in experiment. Our findings call for more studies on unconventional high-temperature superconductors to unearth the consequences of proximity to marginal Fermi liquidness as the prominent candidate in governing the transport anomalies of a strange metal.