Chelsea have completed the signing of Spain left-back Asier del Horno for £8m from Athletic Bilbao.

Chelsea boss Jose Mourinho said Del Horno would be a big addition to the Chelsea squad as they seek to defend their Premiership crown.

“Asier is an outstanding international player who will add quality to the squad in a position we needed to strengthen,” said Mourinho.

The 24-year-old has agreed a three-year deal.

Chelsea have been looking to strengthen their options at left back following the sale last January of Celestine Babayaro. England international Wayne Bridge suffered a double fracture of his left ankle in February, forcing William Gallas to play out of position.

Chelsea chief executive Peter Kenyon told the club’s website: “Jose identified his target to fill the left-back position and we’re delighted Asier has chosen to come to Chelsea.

“The arrival of Asier signifies Chelsea’s desire to strengthen the squad in key positions following a hugely successful season and we all look forward to seeing Asier in the blue of Chelsea in July.”

Del Horno made his debut for Spain last September in a friendly against Scotland and scored the winner against England in November.