Knights CEO Matt Gidley hailed the signing of the 29-year-old second rower.

"Aidan will be a great addition to our young side," Gidley said.

"Aidan is a representative and premiership-winning player who will bring athleticism, experience and leadership to our team from a very successful career to date.”

Guerra will leave the Roosters at the end of the season, having represented the club 140 times since his debut in 2010.

Roosters CEO Joe Kelly said: “Since making his NRL debut with the Sydney Roosters, Aidan has made a significant contribution to the Club and developed into a representative player at both State and National level.

“We thank Aidan for his contribution to the Roosters, and extend our best wishes to him and his young family for the future. In the short-term, we look forward to Aidan continuing to play an important role within our squad for the remainder of the year.

“The Roosters and everyone involved with the Club will always be very special to me, I’ve made some lifelong memories and mates here.

“While it’s sad to be leaving the Club and the boys, I’m pleased to have my future sorted, and my main focus right now is doing the best job I can for the Roosters for the rest of this year.”