Jonathan Calleri is determined to leave West Ham United this month and blames the club for his Premier League nightmare, sources have told ESPN FC.
But West Ham manager Slaven Bilic says the striker should put the struggling club's needs before his desire to leave England.
Calleri joined West Ham on a season-long loan deal from Uruguay's Deportivo Maldonado in August, but he is yet to start a Premier League game or score in nine appearances.
Sources said Calleri feels he has no chance of playing for West Ham again, and wants to return to Sao Paulo -- where he spent the first six months of last year on loan with the Brazilian side and was top scorer in the Copa Libertadores -- or move to La Liga. He would like to play for Sevilla and has been linked to Las Palmas.
The 23-year-old, who played for Argentina in last summer's Olympics, has retweeted several messages from Sao Paulo fans urging him to return to the club.
Calleri has been homesick since he arrived in London and the sources said he feels West Ham have not done enough to help him settle, both at the training ground and off the pitch.
He feels he has not had help learning English or acclimatising to the city, and has been left isolated in a London apartment. He has not felt welcomed by the club's senior players and has even been puzzled by some of the medical treatment he has received, after he missed several weeks with a hamstring injury.
The Hammers are likely to sell wantaway Dimitri Payet before the end of the month, and have already allowed Simeone Zaza to leave, while Diafra Sakho is still injured.
That leaves just fit-again Andy Carroll and rookie Ashley Fletcher as West Ham's only other centre-forwards, and Bilic said Calleri needed to put the club first.
"He is not playing for us at the moment but we don't have too many strikers and he is here, so we have to see what he wants but always what we need," the manager told a news conference on Thursday.
"The team we have now, from Feb. 1, is like that until the end of the season. I always listen to what the players want personally but the most important thing is what the club needs and Calleri's [situation] is down to that.
"It's a difficult situation with him," Bilic added. "He didn't have a good start and he was injured. He is one of the best trainers we have in the squad -- he always gives 100 percent."
A source close to the club said Chadwell Heath, West Ham's training ground, is a welcoming and friendly environment, and suggested that Calleri has been reluctant to integrate with the rest of the squad so far.