The 25-year-old struggled to impress at Camp Nou following his transfer from CA Boca Juniors last summer and will hope the switch will reinvigorate his career. As part of the deal, Barcelona will have the option of extending the loan into a second year.
Riquelme started 22 games last term and scored six goals, but new Barcelona coach Frank Rijkaard has chosen to fill his non-EU places with Javier Saviola and summer signings Rüstu Recber, Rafael Márquez and Ronaldinho.
Riquelme reportedly had the chance of joining Spanish Cup winners RCD Mallorca or newly promoted Real Murcia CF, but instead chose to link up with former Boca team-mates Rodolfo Martín Arruabarrena and Fabrizio Coloccini at Villarreal.
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