To what extent are structural assumptions veiled in extant outsourcing research? In this paper we suggest a unified view on social ties between individuals in outsourcing relationships. In a comprehensive literature analysis of outsourcing research since 2001, we identified structural assumptions and categorize them based on social network measures. Our analysis uncovers two salient patterns: 1) The gatekeeper vs. high density trade-off in interaction between client and vendor employees, and 2) the question whether the strength of ties between individuals can be too high for a professional outsourcing relationship. We present these patterns and other social network structures to formalize assumptions mostly not explicated yet considered important in existing outsourcing research. Based on our results, further research should analyze the impact of these patterns of social structure on outsourcing success.