Santiago, a 34-year-old utility infielder who made the team at the end of Spring Training as a non-roster player, batted eighth.
"I'm ready for any situation," Santiago said. "I know my role. I just have to go out there, try my best and help the team. I want to contribute to the win and not try to do too much."
Santiago became the 24th different shortstop to partner in the middle infield with second baseman Brandon Phillips since 2006.