The former Swindon Town manager recently moved to Ipswich in a scouting role but has now been recruited as assistant manager to new Cobblers boss Aidy Boothroyd.
Jewell said: “We’re disappointed to lose Andy but we wish him well. The job here was on the premise that if he did ever get the opportunity to go back into the coaching fraternity he would do.
“He’s a terrific scout, we wish him well, we wish Aidy Boothroyd well as well.
"We’re on the lookout for another scout now. I’m disappointed that we’ve lost someone who could have been key for us.”