Mauro Zarate leaves West Ham United for Fiorentina after 18 months at Upton Park

Mauro Zarate has paid tribute to West Ham United's supporters after confirmation of his move to Fiorentina came through. The Argentine forward has moved to the Serie A club on a permanent basis after failing to win a regular place in the first team in East London. The move represents the third bout of transfer activity at the club after the arrival of Sam Byram and departure of Diego Poyet on loan.

The 28-year-old has scored four goals in 18 appearances this season, but just half of those appearances have been Premier League starts. With Diafra Sakho, Andy Carroll and Enner Valencia also competing for a place in the Hammers attack, the diminutive forward has struggled to make an impression.

Zarate spent the second half of last season on loan at Queens Park Rangers but his return to West Ham under new boss Slaven Bilic has not seen his opportunities improve. The former Lazio and Inter Milan hitman has penned a parting message to fans, thanking them for their support during his brief spell in England.

"I would like to thank David Sullivan and David Gold for believing in me and for giving me the opportunity of playing at such a special club like West Ham," he wrote in a message on Twitter. "I would also like to thank my teammates for the good times we shared and wish them the very best for the future and especially I would like to thank from the bottom of my heart all the West Ham support for their unconditional support and affection, you are truly unique. Thank you all very much. COYI."

West Ham are expected to attempt to sign a striker during the remaining days of the transfer window, amid injuries to Sakho and Carroll, who will both miss the visit of Manchester City. Co-owner Sullivan believes the club will acquire a loan signing before the deadline, with a view to securing the player on a permanent contract.

"We are looking long-term for a 20-goals-a-season striker," Sullivan told Sky Sports. "There is a possibility that a striker will come in on loan in the next seven days with the option to buy him. He is an overseas striker who has played in higher leagues. It may not happy but it is a possibility, and if all of our strikers are fit we've probably got too many."