Sean Doolittle, Baseball's Left-Wing Lefty, Retires
Sean Doolittle Announces Retirement - MLB Trade Rumors
Sean Doolittle retires after 11 MLB seasons with a 'full heart
Sean Doolittle retires after path led to All-Star, World Series honors
Washington Nationals reliever Sean Doolittle heads to IL with sprained elbow - ESPN
MLB players who could retire this offseason
Washington Nationals' closer Sean Doolittle almost got a shot at an All-Star moment in Washington, D.C. - Federal Baseball
Nationals pitcher Sean Doolittle announces his retirement after more than a decade in the majors
Sean Doolittle, Baseball's Left-Wing Lefty, Retires
Sean Doolittle, part of Nats' World Series team, retires - The Washington Post