Middlesbrough boss Aitor Karanka has confirmed that he dropped winger Mustapha Carayol from his squad to face Leeds last week.
Karanka says he was not happy with the Gambian's 'attitude' and therefore did not select him.
Sky Sports understands the 25-year-old was told not to train in the build-up to the Leeds match following an argument between the pair, making it inevitable that he would not be involved on Saturday against Leeds.
"He wasn't injured, I didn't like his attitude. I prefer to talk about the players who were in the game," said Karanka
The Spaniard did insist that Carayol could be involved against Sheffield Wednesday and said: "If he trains well this week he has a chance to play, yes."
The news that Carayol was not involved came as a big shock to the Boro faithful, given the winger's good form since the turn of the year.
The news is also likely to alert a number of rival clubs after Boro fended off interest from the likes of Brighton and Nottingham Forest in January.
We also understand that Carayol has thus far stalled on signing a new contract with the club, as Boro look to tie him down to a long-term deal.
It remains to be seen in light of the bust-up with Karanka, whether Carayol will be persuaded to commit his future to the club.
Karanka's fall out with Carayol came after he spoke out about some of his players after their loss at Watford. It is reported Carayol was one player targeted, although he was only a substitute introduced at half-time at Vicarage Road.
"I was very disappointed with the attitude of some players in the Watford game," said the Boro boss.
"I was not happy (on Saturday) because we didn't win, but I was happy with the attitude of all the players on the pitch. If we play in this way then the wins will arrive.
"The team was good. I don't want to say that we deserved to win, but we played well. More important than whether we played well or bad, though, is the fact that the attitude is right."