Doncaster have signed Tongan International Fotu Lokotui until the end of the season.
The back row featured at the World Cup for his country, coming on as a replacement in their fixture with Argentina.
The 27-year-old has played 14 times for his country and arrives from Counties Manakau in the Mitre 10.
This year he joined the Asia Pacific Dragons, based in Singapore and who play in the Global Rapid Rugby. He played the first half of the season with them before joining the franchise Samoan side Samoa Kagifa in the same league.
Fotu arrived in Doncaster yesterday and will begin training with the Knights next week ahead of the home game with Newcastle Falcons.