Being informed that his injury was career ending, he knew that his career was all but done. Before the operation he could heave a ball 85 yards; afterward he struggled to reach 35.
The passage describes the impact of an injury on a player's ability to perform their sport.  He was informed of his career-ending injury and realized that his playing days were over. Before surgery, he could throw a ball 85 yards; after the operation, he struggled to reach 35 yards.