Argentine striker Jonathan Calleri has completed a season-long loan move to West Ham from Uruguyan club Deportivo Maldonado.
The 22-year-old linked up with his new team-mates at training on Tuesday and will go straight into the squad for Thursday's Europa League play-off first leg with Astra Giurgiu in Romania.
The forward topped the 2015 Copa Libertadores scoring charts with Sao Paulo, and has also enjoyed a fruitful stint at Boca Juniors.
"I am very happy to have signed for West Ham," Calleri told West Ham's official club website.
"This represents a fantastic new challenge for me and I am really looking forward to it.