Perhaps Chip Kelly isn't as close to Bill Belichick as we think.

Houston Texans linebacker coach has rejected an offer from Kelly to become the San Francisco 49ers next defensive coordinator.

Vrabel, 40, remains close to Belichick having played for him for several years, while Kelly shares an obvious connection to Belichick as well.

Vrabel joined to the Texans coaching staff with Bill O'Brien in 2013, another coach with an obvious connection to the New England Patriots.

A defensive coordinator job would obviously be a promotion for Vrabel, but it's possible that he decided to remain in Houston as a defensive coordinator in-waiting when a 68-year old Romeo Crennel decides to retire.

It's either that, or Vrabel decided against running the defense for a head coach in Chip Kelly who doesn't seem to care about time of possession and/or how long his defense is out on the field for.

2015 defensive coordinator Eric Mangini remains with the 49ers.