Nick Civetta made the permanent move to Castle Park in the summer of 2018.
The former Newcastle Falcons lock joined the Knights on loan in the 2017/18 season, making 10 appearances.
Nick signed for the Falcons from Italian Serie A side I Medicei, while the second row previously played for fellow Italian sides SS Lazio and Viadana.
The 30-year-old took up rugby at a late age of 18 when he attended Notre Dame University in USA. Civetta has also featured for the USA select side three times and was selected for the USA Rugby All Collegiate All-American team.
In the 2016/17 season, the New Yorker made his way into the USA national side and was key player as they secured a Rugby World Cup 2019 place, beating rival nation Canada over two legs.