West Brom manager Tony Pulis says he has never dealt with someone who has "faded" as badly as Saido Berahino.
Berahino was expecting a move to Tottenham in the off-season but a reported £25million deal never eventuated.
The 22-year-old has struggled in recent weeks, with Pulis stating Berahino has been a "really big disappointment" this season.
"It is the first time I have had to manage this situation," he said. "I have been in management a long time but it is the first time someone has faded as badly as Saido has after a move fell through.
"But you can't condemn people. We have to accept what has happened and try and get the best out of him.
"Some people listen first time and others take a little bit more time to listen. People react differently - we are not all the same.
"You have to accept, today more than ever, that when you are managing young people they are a different breed to what we were. He is a young lad and he has been given everything. He has everything at his feet really.
"You have to try and work him through that minefield. He has got to make sure that he gets his head in gear and performs well.
"If something comes up it comes up, if it doesn't he has to perform. He has to recognise he has to play football and do his best for West Bromwich Albion.
"Saido at his best should be in our team. He has been a really big disappointment for us this season."
Berahino is expected to start against Swansea City on Boxing Day, with Salomon Rondon suspended.