Costner is part-owner of the Lake County Fielders, the newest team in the independent Northern League.
Friday night, he flipped the lights on at the team's stadium in Zion for the first time, and he talked about his decision to join co-owner Rich Ehrenreich in the venture.
"My first instinct was, no I'm not from there, it's not appropriate - but Rich convinced me it was," said Costner. "I'd made three movies about baseball and it was part of the fabric of America, and it was appropriate."
Costner's team is not playing in Zion Friday night.
This was his only chance to visit the field before the first night game on Monday.