The Nittany Lions will look to win their fourth straight AHA Championship.
Johnson will join Kieger's coaching staff after being an assistant coach at the University of Miami.
The game will take place on June 8 at Rate Field in Chicago.
The Nittany Lions will look to rebound after a disappointing season last year.
The defending champions will play 16 matches against teams that made last year's NCAA Tournament in their 30-game schedule.
Throneberry is the seventh Penn State baseball player to enter the transfer portal.