Italy international Simone Zaza will not play for West Ham United again because of the terms of his contract, manager Slaven Bilic said on Thursday.
The 25-year-old striker was signed from Juventus on a season-long loan last August for an initial fee of five million euros (4 million pounds), but has been a big disappointment for the club's supporters.
A permanent fee of 20 million euros is automatically triggered once he makes a given number of first-team appearances, 15 according to local media.
Zaza has featured 11 times so far, eight in the league, with no goals scored. The only time he has scored at the London Stadium was against West Ham for Juventus in a pre-season friendly.
He has not played in the league since November.
"He is still our player until he goes somewhere but mainly because of the situation with his contract he is finished here," Bilic told reporters.
"Unfortunately we had to judge him on six, seven, eight games which is not a big pattern to judge a player in general," added the Croatian.
"He is definitely a good player but like many times in football, it just didn't happen."
The Hammers have their eyes on Sunderland striker Jermain Defoe, who started his career at the East London club, but have so far been rebuffed by their relegation-threatened rivals who cannot afford to lose their top scorer.
"He has the most important thing in the game: goals," said Bilic of the 34-year-old who has scored 11 times in 20 Premier League games. "He converts most of his chances to goals."