Virtualization fundamentally changes how social relations form, but its effect on network structure in collaborative teams is poorly understood. This paper compares team networks from nine government-funded projects that were conducted virtually because of the COVID-19 pandemic with 15 prepandemic projects from the same funding program. Results of our comparative analysis of 2,746 dyadic ties in 24 teams showed lower levels of network density, clustering, and structural cohesion in virtualized projects, indicating fragmented virtual teams. Furthermore, expressive networks, defined by the sharing of personal information, were affected more than instrumental networks, which revolve around the sharing of expert knowledge.