The Nittany Lions jumped six spots in the latest poll.
Alex Stevenson and Kris Shakes were named the conference's Big Ten Offensive and Defensive Players of the Week Tuesday.
In the Nittany Lions' Penn State Invitational performance, Mruzik registered 53 kills, 14 digs, eight blocks, and three aces.
Saturday's game featured a stellar performance from sophomore quarterback Drew Allar and strong play from the team's wide receivers and defensive secondary.
The Nittany Lions fell six spots from their previous preseason position at No. 5.
The Lady Lions begin an 11-game non-conference slate on November 7 at home against Bucknell.