We introduce an operational notion of admissibility for quantum dy-namics defined as the diamond-norm distance of a physical channel froma restricted class of locally implementable channels. For a two-qubit en-tangling family Uθ = e−iθX⊗X , we prove that the noiseless admissibilitydistance to the identity channel equals 2| sin θ|. Extending to locally de-polarized dynamics Eθ,p = (Dp ⊗ Dp) ◦ Uθ , numerical semidefinite-programevaluation reveals a robust factorization δ(θ, p) ≈ 2 sin θ f (p), with f (p)well-approximated by (1 − βp)α over p ∈ [0, 0.6]. The resulting quantitycaptures channel-level nonlocal capability independently of state-specificoutput correlations, as illustrated by probe states that remain uncor-related despite nonzero admissibility distance. These results provide aminimal operational framework for quantifying dynamical deviation fromlocally admissible processes and establish a tractable testbed for furtheranalytic development