Craig Hignett has revealed that he left his role as Middlesbrough assistant after he and head coach Aitor Karanka fell out.
The former Boro midfielder, who made almost 200 appearances for the Teesside outfit, left his position in December.
At the time, Karanka said that there were "differences" between the two, and now Hignett has spoken out.
"If I'm honest I had a falling out with the head coach," Hignett told Sport 360. "Me and Aitor had a disagreement and unfortunately it couldn't be rectified and I left. We obviously couldn't work together and that was disappointing. Boro is my club. I spent almost 20 years at the club in one capacity or another.
"It was just a clash of personalities if you like. I'd worked with Aitor and got on well with him at the start but things deteriorated towards the end.
"Myself and Aitor weren't compatible with each other. I couldn't put up with some of the things that were happening there and he probably couldn't put up with some of the things I wanted or could see happening. Unfortunately these things happen in football sometimes and you learn to get on with it."
Boro are chasing promotion to the Premier League and go into the final seven games of the Championship season only out of the automatic promotion places on goal difference.