# What We Keep of What We Forget: Replacement Operators and Routing Semantics in Training-Free MoE Expert Pruning > Source: > Published: 2026-11-04 04:35:08+00:00 Training-free expert pruning makes two decisions: which experts to remove, and what the layer computes when its router still selects a removed expert. Published methods change both at once. Holding the mask fixed, we compare replacement operators from three families on OLMoE, DeepSeek-V2-Lite and Mo