Garrido, 22, has agreed a four-year deal after the Swede paid the Spanish club $3.75million for the player's services.

He was looking for a new challenge after Sociedad's relegation from the top flight.

Garrido is Eriksson's fifth signing since he took over and joins Rolando Bianchi, Martin Petrov, Gelson Fernandes and Geovanni at Eastlands.

Eriksson, with the backing of chairman Thaksin Shinawatra, is working at a fierce pace in the transfer market with the start of the season only nine days away.

The former England coach still has more business to do in that respect as well.

Striker Valeri Bojinov has claimed he is moving from Fiorentina to join fellow Bulgarian Martin Petrov at Eastlands.

There is also speculation that defender Vedran Corluka and midfielder Elano are about to come on board from Dinamo Zagreb and Shakhtar Donetsk.

Eriksson would only say, however: "Something has to happen soon as the league is about to start."