Eric Byrnes isn’t done playing pro ball.The former A’s outfielder signed a two-day contract with the independent San Rafael Pacifics of the Pacific Associations and will suit up Aug. 5 and 6 at Albert Park.“This is a thrill for me to go back to the roots of baseball,” Byrnes said. “The Pacifics and all of Indy ball are what it’s all about – a close connection with the fans and with the community. The guys I’m playing with are not in it for the money or fame; they do this because they love the game. I’m proud to be a small part of it.” Byrnes, 38, has a cause beyond returning to the field. He’s raising funds for the Pat Tillman Foundation, which supports veterans and spouses through educational scholarships and a social network.The Pacifics are donating a portion of the ticket sales for both of Byrnes’ appearances to the foundation, and Byrnes has agreed to donate his Pacifics salary.Furthermore, he’ll donate $1,000 for each of his walks, steals and singles, $2,000 for a double; $3,000 for a triple and $10,000 for a homer. Plus, $500 for every ball he catches.In an email to the Pacifics media relations manager, Vincent Espinosa, Byrnes wrote, “Let’s make it $100,000 for a grand slam, just in case ”Good stuff.Byrnes last played for the 2010 Mariners.John Shea/San Francisco Chronicle