Aitor Karanka appears on the brink at Middlesbrough after the Championship title contenders confirmed the Spaniard will not take charge of Sunday's fixture at Charlton Athletic.
Rumours in local media on Friday suggested that Karanka had walked out of a furious meeting with players - the former Real Madrid assistant angered by Boro's midweek defeat at Rotherham United - and threatened to quit his job, despite the Teesside club sitting second with 11 games to play.
It has been claimed that Karanka told his players he would be leaving the club, having accused them of lacking "desire" at the New York Stadium.
A statement from Riverside Stadium officials on Saturday read: "Middlesbrough Football Club can confirm that Aitor Karanka did not take training on Saturday morning.
"Assistant Head Coach Steve Agnew will take charge of the team for Sunday's fixture at Charlton Athletic.
"We appreciate supporters will want to know further details, but at this time the club cannot make any further comment and is solely focused on Sunday's game at The Valley."