BUFFALO, N.Y. -- One Ryan wasn't enough for the the Buffalo Bills.
Rob Ryan, the former New Orleans Saints defensive coordinator who was fired in November, will be joining the Bills as assistant head coach for defense after Rex Ryan hired him Sunday.
"I'm excited to have Rob join our staff, and I think he will be a great asset for our defense," Rex Ryan said in a statement. "He has a tremendous working knowledge of our schemes, and I look forward to his input."
The Ryan brothers have not worked on the same staff since 1995, when both were assistants with the Arizona Cardinals under their father, Buddy Ryan.
"On a personal note, it's been a number of years since we have worked together," Rex Ryan said. "And so we are both really looking forward to this opportunity."
The move comes after Ryan and team officials traveled to Florida for end-of-season meetings with Bills owners Terry and Kim Pegula.
Last season, Buffalo was led on defense by coordinator and longtime Rex Ryan assistant Dennis Thurman. The Bills did not mention any other staffing changes beyond the addition of Rob Ryan.
Asked about Thurman last week, Rex Ryan would not comment specifically.
"I don't want to say anything until we talk to our coaches," Ryan said. "Some coaches may want to be here, may not want to be here, whatever it is."
Asked Dec. 10 about a possible reunion with his brother, Rex Ryan said, "You never say never. ... It is fun to be around him, there's no question about it, and I know he's a great coach. But I think we purposely have tried to set different courses and things. But I never rule out that possibility. Obviously, he's a great coach, and if that happens, that'd be great."
Rob Ryan spent a week with the Bills' coaching staff at their facility in December and wore team-issued Bills gear prior to a game against the Philadelphia Eagles.
"It was great to have him out there," linebacker Preston Brown said then. "It was kind of weird because they have the exact same voice. So you kind of hear somebody talking, and you think it's [Rex], but it's his brother. So it's cool having another great mind out there to help us get through the week."
Hired in January after six seasons with the New York Jets, Rex Ryan closed his first season in Buffalo with an 8-8 record, and the Bills extended the NFL's longest active playoff drought to 16 seasons. The Bills' defense fell in several statistical categories this season and finished 19th in yards allowed and 15th in points allowed.
Rob Ryan has 28 years of coaching experience, including 17 at the NFL level. He won two Super Bowl titles as a linebackers coach in New England from 2000 to 2003. He has also had stops in Oakland, Cleveland, Dallas and New Orleans.
In 2013, Ryan's first season in New Orleans, the Saints finished fourth in yards allowed and jumped 28 spots in the rankings. This season, that defense ranked last in the NFL in both yards allowed and points allowed before Ryan was fired following the team's 47-14 loss to the Washington Redskins in Week 10.
Information from ESPN staff writer Mike Rodak and The Associated Press was used in this report.