This study integrates research on newcomer socialization and work teams to examine how the team environment facilitates or hinders the translation of human capital into newcomer performance in professional sports teams. Using large, multiyear and multilevel data from the top five European professional football leagues, we examine how individual-level newcomer human capital and the team-level characteristics (prior team performance, number of newcomers) influence individual newcomer performance during two different socialization contexts (when more vs. less time for socialization is provided). We found that individual human capital was positively related to newcomer performance across socialization contexts while the direct relationships between team variables and performance were conditional on the socialization context. Prior team performance was positively related to newcomer performance when more time for socialization was provided, but prior team performance as well as the number of newcomers were negatively related to newcomer performance when less time for socialization was provided. Beyond the direct relationships, our results show that human capital was less positively related to newcomer performance when newcomers joined higher performing teams across socialization contexts. These findings extend our understanding of the complex relationships between individual human capital and the team's socialization environment on newcomer performance and advance new knowledge regarding conditions that facilitate the success of newcomers who join existing (operating) teams.