Rucci comes from Wisconsin with two years of eligibility remaining.
"To me, college basketball was about The Palestra on a Saturday afternoon, and it could be 10º outside, but it was always hot."
Mayer spent one year at Wisconsin and has no recorded appearances or statistics.
Beamon was the third Nittany Lion to announce his return.
Potts spent one season at Penn State after four years at Minnesota.
Ellies was the second Nittany Lion to announce his return to the team after tight end Tyler Warren.