The “sophomore slump” is a widely accepted phenomenon in modern sport culture, commonly conceptualized as a decline in performance during a player’s second year of competition following an outstanding first season. This study empirically verified the absence of sophomore slump through a two-stage network data envelopment analysis and Malmquist productivity index analysis of 616 English Premier League players from the 2014–2015 to 2018–2019 seasons. The relative rankings of individual second-year players were compared with their rankings in the previous season, and second-year and non-second-year player groups were also compared. No evidence was found to indicate the existence of a sophomore slump. In addition, Tobit regression analysis was conducted to analyze the effects of environmental variables such as yellow cards, red cards, and fouls. This study is meaningful because it analyzes “efficiency,” which has a strategic and financial impact not only on individual players but also on team managers and scouts.