Tony La Russa, right, attends the CEO panel of the Williston Basin Petroleum Conference in Bismarck.

BISMARCK – The Williston Basin Petroleum Conference had a surprise guest Thursday who wasn’t on the lineup card.

Tony La Russa, a three-time World Series championship manager, attended the CEO panel to hear his friend and Continental Resources CEO Harold Hamm speak.

La Russa said he was talking to Hamm a few weeks ago about North Dakota oil development and he wanted to learn more.

The timing of the conference worked out well with La Russa’s plans to attend a Minnesota Twins game, he said.

After Hamm’s speech, La Russa planned to accompany other Continental Resources executives to tour a producing well and a drilling location north of Belfield, N.D.

“I can’t wait,” La Russa said. “I’m just fascinated by it.”

La Russa, who ranks third on baseball’s all-time wins list for managers, retired from the St. Louis Cardinals after their World Series win in 2011.