All post-classical effects in quantum field theory arise from various "corrections" that come from what you could define as virtual particles, whether it's from

All post-classical effects in quantum field theory arise from various "corrections" that come from what you could define as virtual particles, whether it's from the perturbative treatment or a numerical lattice gauge calculation. In the latter, you need to (formally) sum over all possible field configurations, the majority of which will contain half-witted weird off-shell "particles" and the entire spectrum between stuff you'd never see as a particle and the classical resonances. It is more clearly visualized in a perturbative expansion, for sure, but it's a bit disingenous I think to argue that there are no virtual particles in a lattice calculation.