Viruses are the most abundant biological entities in the world's oceans. Their potential control on the dynamics and diversity of bacterioplankton and some phytoplankton groups, and consequent effect on the flow of energy and matter in food webs, may be argued as beyond dispute. Paradoxically, their importance seems to be persistently underestimated by marine modelers, frequently by exclusion, despite the uninterrupted volume of knowledge advanced during the past decades. Bridging the gap between knowing and modeling the role of viruses is, undoubtedly, one of the upcoming frontiers to be crossed in modeling the plankton. This paper has a two-fold objective: (1) review the knowledge on the roles of viruses in marine systems that has been put forward over the past decades, and (2) see how viruses have been incorporated into marine ecosystem models, along with the factors that are limiting their inclusion.