Isaac Success made the move to the Premier League last summer, joining Watford from Spanish side Granada for £12.5million.
However, despite his considerable price-tag, the 21-year-old has been restricted to just a handful of starts for the London club this season.
And according to the midfielder's former youth team coach Douglas Idahosa, if he does not receive assurances about his game time, he will leave.
And Premier League rivals West Ham are said to be waiting in the wings to snap up the Nigeria international.
Speaking to website AllNigeriaSoccer, BJ Foundation academy coach Idahosa said: "It is true that West Ham are interested in signing Isaac Success.
"If he is not promised first-team opportunities he will move before the window closes."
And it is not the first time Success has been linked with a rival London club, with reports claiming Chelsea tried to sign the midfielder in 2014.
"Chelsea were interested in signing Success," Idahosa said last month.
It is true that West Ham are interested in signing Isaac Success
"They said the board first had to hold a meeting to approve the transfer. They wanted to pay £1.2million, that sort of range.
"Michael Emenalo [Chelsea director] contacted our agent and a four-year deal was offered.
"They were slow, they were asking us to hold on and we couldn't wait. Granada were faster and we finalised everything with them within three days."
Success only made 19 appearances for Watford this season, starting just two Premier League games.