Middlesbrough have confirmed the appointment of former player Craig Hignett as assistant head coach.
The 44-year-old left his role as Colin Cooper's number two at Hartlepool to return to Boro, where he played between 1992 and 1998 before working on the club's academy coaching staff.
Jamie Clapham had been assisting Karanka since he took the reins in October and he will now return to work with Middlesbrough's under-21 side.
"We're delighted that Craig has decided to join us and I'm sure everyone will join us in welcoming him back to the club," Boro chief executive Neil Bausor told the club's official website.
"We firmly believe that Craig's experience is a great fit for us and will make an excellent addition to our coaching staff."