The 23-year-old told the official site, “I am very happy to sign and grateful to Alan Curbishley and West Ham United for choosing to sign me.
“I have had a few little problems at Sevilla but I am now looking forward to a new beginning in England and I hope to enjoy a good period with the club.
“I am confident that my style of play can fit into the Premiership, and I am excited by the prospect of playing against the best teams in England, but first I must simply try to win a place in the team and help us out of the position we are in.