Saints have added to their centre options by capturing former Bristol player Luke Eves.
The 26-year-old ended his stay at the Championship club after they lost the two-legged play-off final against Worcester Warriors in May.
Eves, who played for England in the 2009 World Rugby Under-20 Championships final, has joined on a short-term deal.
He will add cover to the Saints squad during the World Cup, which will see centres Luther Burrell and George Pisi in action for England and Samoa respectively.
“With a number of players away with their countries for the World Cup we felt we needed some more depth in the squad,” said Saints director of rugby Jim Mallinder.
“Luke is a good player who has plenty of experience in the Aviva Premiership and in the Championship, and we believe he has the quality to be able to contribute as our season gets underway.”