Swansea have completed the signing of Jordi Amat from Espanyol for a £2.5million fee, subject to the defender completing his medical.
The 21-year-old has long been on manager Michael Laudrup's radar, and he becomes the second summer arrival at the Liberty Stadium, with the services of Real Betis midfielder Jose Canas already secured.
A statement on the Swansea website said: "Swansea City have completed the £2.5m signing of central defender Jordi Amat from Espanyol, subject to a medical and international clearance."
Amat, who spent last season on loan at Rayo Vallecano, has agreed a four-year contract.
Swansea have made offers for a number of players over the past couple of weeks, with Amat the first among them to join the club.
The Swans have tabled potential club-record offers for Lyon striker Bafetimbi Gomis and Vitesse Arnhem's Wilfried Bony, with the fee for the latter understood to be around the £10million mark. Bony's agent, Francis Kacou, had told Arnhem newspaper De Gelderlander a £10.2m deal had been done for the Ivory Coast international.
But Vitesse posted a statement on their website which read: "Various media have reported that Wilfried Bony is to transfer to Premier League club Swansea City. This message is incorrect.
"There is admittedly much interest in the striker, the top scorer in the Eredivisie last season, and Swansea City are one of the interested clubs. However, a transfer is not the case."
Despite Vitesse's statement, Press Association Sport understands a deal is likely to be completed in the coming days for Bony to become Swansea's record signing, as Laudrup looks to ease the goalscoring burden on Michu. The fee would almost double the £5.55million paid for Pablo Hernandez last summer.
Real Betis midfielder Alejandro Pozuelo is also set to join his former team-mate Canas in south Wales, while Swansea are looking to bring Jonathan de Guzman back to the Liberty Stadium on a second season-long loan. Bids have also been lodged for Birmingham winger Nathan Redmond, and Standard Liege forward Michy Batshuayi.