New manager Aidy Boothroyd moved quickly to snap up the experienced Higgs as his first signing this week and has also opted to allow loanee Sam Walker to return to Chelsea.
Boothroyd, who is keen to wheel and deal in January and has been linked with Kidderminster striker Jamille Matt, told BBC Radio Northampton: "I explained to Sam that Shane would be my first choice.
"Sam accepted the decision like the good professional he is and it was decided he would return to Chelsea.
"It is in the interests of both Chelsea and Sam that he is playing regular first team football, but I explained that wasn't going to be the case here."