Worcester Warriors director of rugby Dean Ryan has described the signing of Donncha O'Callaghan as a "real coup" for the club.
The veteran Ireland lock joined the Warriors from Munster on Thursday.
Ryan believes that O'Callaghan's experience will be valuable during the new season.
"The opportunity to bring someone in with such international and European experience is a real coup for the club," he told Worcester's official website.
"It's important to get a balance of proven and experienced performers and young developing talent integrated within the squad.
"Donncha has tremendous know-how at the highest level and will be able to offer our younger players a great deal of advice. His experience and leadership can only be of benefit to the team as we prepare for life in the Aviva Premiership."
O'Callaghan has been caped 94 times by Ireland since 2003.