Hudson, who is the Nittany Lions' first transfer portal addition, scored a touchdown against Penn State this season.
"Beau Pribula did not want to leave our program, and he did not want to leave our program until the end of the season."
Sellman had 219 kills in 20 matches as a freshman this season.
The Nittany Lions received 90 votes last week.
Thomas Robinson, listed as a World Campus student in Penn State's directory, faces 18 felony counts.
Allar's news came after backup Beau Pribula announced he will enter the transfer portal.
Notifications