Influence of sports has been substantial on american literature in the twentieth century. Examples are the works of Ring Lardner, Frank Merriwell and John Tunis. Sports had profound influence on the fictions of F. Scott Fitzgerald (football and baseball in The Great Gatsby), Thomas Wolfe (football in the Web and the Rock) and Ernest Hemingway (fishing and bullfight in The Old Man and The Sea, The Sun also Rises).
Baseball is often read as the defining element of US's independence from the European tradition. It is widely used in the contemporary novel as a metaphor for some uniquely American political and individual thought - for baseball in US lit, and sport more widely conceived, see Coover's Universal Baseball Association, Roth's Great American Novel, DeLillo's Underworld, Mailer's The Fight (boxing), Wallace's Infinite Jest (tennis).
"Rabbit Run" by John Updike, around a 26-year-old former high school basketball player named Harry "Rabbit" Angstrom and his unhappy life, is a bitter metaphor around being popular and successful as a young sport practitioner but failed at life.