A string of withdrawals ⁠from the Canadian Open underscored concerns ⁠that professional tennis’s lengthy calendar and expanded top-level ⁠events are increasing injury risks, the Professional Tennis Players Association has said. The players’ advocacy group said it was saddened but not surprised by the absences from the tournament, arguing that reduced recovery time between tournaments was contributing to injuries occurring earlier in the season and becoming more serious. In Montreal, the men’s...