It has long been known that galaxies in clusters are more likely to be of early type and to have lower star formation rates than galaxies in the field. Over the past decade observations have shown that these effects extend well beyond the cluster virial radius, suggesting that galaxies may have been preprocessed, perhaps by group or filament environments, before they fall into clusters. We investigate this possibility by means of numerical simulations focusing on groups merging with clusters. In particular, we look at the gravitational influence of the merging group versus the cluster and the persistence of group substructure within the cluster. We also study enhanced group dynamics within a cluster and the effect of the diffuse hot gas component.