KANSAS CITY, Mo. — The Chiefs’ coaching staff is getting the old band back together. Or, at least one former member. A day after Eric Bieniemy’s reported return, the Chiefs announced on Friday the hire of Matt Nagy as senior assistant/quarterbacks coach. The 43-year-old Nagy originally joined Chiefs coach Andy Reid’s staff in 2013 as quarterbacks coach before being promoted in 2016 to offensive coordinator, a position he held for two seasons. The Chicago Bears hired Nagy in 2018 as their head coach, but he was fired after the team went 6-11 this past season. In four seasons as the Bears’ head …