AITOR KARANKA has warned his Middlesbrough players to be wary of the threat posed by their former team-mate Diego Fabbrini tonight, after admitting he was surprised by the Italian’s negative response to being dropped to the bench earlier in the season.

Fabbrini made 22 Championship appearances for Boro prior to the turn of the year, but saw his loan from Watford cut short to enable him to make a £1.5m move to Birmingham in January.

He is expected to be part of the Birmingham starting side that will line up against Middlesbrough on Friday night, in a game that could see the Teessiders move three points clear of promotion rivals Burnley and Brighton, who do not play until Monday.

Provided Boro claim at least a point at St Andrew’s, they will head into their final game against Brighton knowing a win will guarantee promotion, but Karanka expects Fabbrini to pose a considerable threat.

“I liked him, and that’s why I brought him here,” said the Boro head coach. “It was a surprise for me when he was a little bit disappointed that he didn’t play more games. I can understand that because, as a player, you always want to play.

“Now, I think he has been unlucky because he is not playing the games he was expecting to play, but he is a real threat. He is a really good player, he can make the difference and for that reason we have to be careful with him. But we are at an advantage because we know about him.”

Fabbrini’s departure paved the way for Gaston Ramirez’s January loan move from Southampton, but Karanka claims he would happily have held on to the Italian had he been willing to accept a less central role in the team.

“Could he have stayed? Yes,” said the Boro boss. “But I can't guarantee any player that he will play in every game and he decided to leave because he thought he was going to play more than at Birmingham. For that reason I don't want to keep a player who is not 100 per cent happy here.”

Karanka claims George Friend has not been ruled out of Friday night's game, but admits he is reluctant to play the full-back, who is nursing a hamstring injury, in the hope of him being fit to face Brighton.

“We are just waiting for George to see if he can play on Friday,” said Karanka. “I will check him today because he's desperate to play but I don't know if he's 100 per cent and when we have another important game (after Birmingham) I don't think it is good to take a risk.”