Zarate only signed for the Hammers in the summer, but looks set to move on loan to Loftus Road
Zarate was signed by the Hammers in the summer from Club Atletico Valez but has failed to establish himself in the side, with Diafra Sakho, Enner Valencia and Andy Carroll all preferred ahead of him at the club by manager Sam Allardyce so far this season.
Zarate has scored two goals in eight games since arriving at the Boleyn Ground, but reports have been linking him with a move to Loftus Road in recent days, and have gathered pace, and should be able to make his move .
The news was confirmed as Allardyce addressed reporters ahead of the New Years' Day clash against West Bromwich Albion at the Boleyn Ground, and he looked back on 2014 as a 'magnificent' one both on and off the field.
West Ham have managed to avoid relegation, and built on it at the start of this season, currently sitting sixth in the Premier League - two points off the Champions League places, and the club announced yesterday record pre-tax profits of £10.3 million.
Allardyce told reporters: "As a year, 2014 has brought us 56 points and that is a magnificent year. When we came out of the dark side of January since then we've had one magnificent year. From the football side and the financial side too."
The Hammers have lost their two games over the festive period so far, having faced Chelsea and Arsenal, but are looking to bounce back against a side that has just sacked their head coach in Alan Irvine.
"For us it's about trying to re-establish our home results and whatever position West Brom are in, they're still a talented side.
"We need to make sure we're spot on and ensure there's no hangover from the two defeats."
James Tomkins is suspended for the visit of West Brom but Carl Jenkinson and James Collins are available with West Ham close to having a full strength squad available.