Clifford was Penn State's leader in wins as a starting quarterback, passing yards, total yards, and passing touchdowns.
Castro-Fields appeared in eight games for the Commanders last season.
Amos played for Penn State from 2011-14.
The former Penn State wideout was signed as an undrafted free agent in 2023.
Oruwariye signed to the Jaguars' practice squad in October 2023.
Robinson became the second Nittany Lion released by the Giants this week.