Sam Patrick Gordon was the new arrival -- weighing in at 8 pounds, 15 ounces. Gordon and his wife, Jamie, also have a son Max, who was born in September 2010.
The birth was in the Kansas City area and Yost said he expected Gordon to be back in the lineup on Tuesday night against the Marlins.
In his absence, David Lough played left field.
Dick Kaegel is a reporter for MLB.com. Kathleen Gier is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.