Saints coach Sean Payton has chosen Rob Ryan as his new defensive coordinator, hoping he can overhaul a New Orleans unit that was historically bad last season.The Dallas Cowboys fired Ryan in January after two seasons as defensive coordinator."We have experience in preparing and playing against his defenses and they've always been challenging in terms of the different looks and pressures that they feature," Payton said when Ryan's hiring was announced Saturday, one day after he interviewed for the job. "We've had the chance to visit with each other and talk about our visions for our team and I'm excited about moving forward as we prepare for the 2013 season."The Saints yielded 7,042 yards last season, the worst single-season total in NFL history.Just days after returning from his season-long suspension, Payton fired defensive coordinator Steve Spagnuolo and said the team would switch defensive schemes from a 4-3 alignment to a 3-4, the scheme Ryan ran with the Cowboys.Ryan has run 3-4 schemes for years. He worked as a linebacker coach in such defenses in New England, where he was part of two Super Bowl-winning teams. He then spent five seasons as defensive coordinator in Oakland (2004-2008), followed by two seasons in Cleveland before moving to Dallas in 2011.Boldin says he'll retire if releasedAnquan Boldin told NBC Sports Network that he will retire if released from the Ravens as Baltimore attempts to deal with salary-cap restrictions next season."I won't play in another uniform," said Boldin, who has been with the team since 2010. "We have a saying, once a Raven, always a Raven, and I'll always be a Raven."The 32-year-old wide receiver is due $6 million next season, the final year of a four-year contract, but money could be tight. Six starters head to unrestricted free agency, including quarterback Joe Flacco, linebackers Dannell Ellerbe and Paul Kruger and safety Ed Reed.The Ravens could retain Boldin at his current salary or do a salary-cap-friendly extension. Though the Ravens have not broached that possibility with Boldin, The Baltimore Sun reports, it is regarded as a possibility the team might look into.