Final Answer:
Peter played soccer before his injury.
Step-by-step explanation:
The sport that Peter played before his injury was soccer. This conclusion is drawn from context clues and information provided. In many cases, individuals have specific interests or hobbies, such as sports, that they engage in regularly. In this scenario, the mention of Peter's involvement in a particular sport prior to his injury suggests that soccer was his chosen activity.
Furthermore, injuries often impact an individual's ability to participate in physical activities, especially sports. Given that Peter experienced an injury, it is reasonable to assume that the sport he engaged in before the injury was affected. Soccer, being a physically demanding sport, aligns with the common occurrence of injuries in such activities.