Chairman Steve Gibson keeping faith with Spanish boss.
The Spaniard walked out of the club on Friday last week after a bust-up during a team meeting, telling players he did not want to manage them again and that he would not return.
When he tried to return to apologise on Saturday he was turned away from the club, as chairman Steve Gibson considered his position, which included sacking him.
Assistant Steve Agnew was put in charge of the team for Sunday's loss at Charlton but now Gibson has decided that Karanka can return and will be back in the hot-set on Tuesday, as the club prepare for their crunch game with rivals Hull City on Friday.
A statement released by the club on Monday confirmed: Middlesbrough Football Club can confirm that Head Coach Aitor Karanka will be resuming first team duties with the club with immediate effect.
"We have 10 games left this season and as a club we are fully focussed on what remains of our Championship campaign."
Middlesbrough currently sit second in the Championship table seven points adrift of leaders Burnley, but two points ahead of Hull.