In my opinion under the circumstance that he would be fired, Phillips will be here until Jones has someone in mind to take over his defense. He's not going to overhaul the 3-4 and put us back into a rebuilding mode, so a 3-4 defensive coach will be found first. Let me add that the new defensive coach wouldn't necessarily be brought in as a head coach replacement. He would probably back up the newly promoted-to-head coach, Jason Garrett because one thing's for certain. Jones will not hire a head coach and in turn allow him to set up his own staff.
Answer: sometime during the offseason.