Arsenal had previously officially announced the signing of 26-year-old midfielder Zubimendi from Real Sociedad, who also posted photos to commemorate them through social media.
Zubimendi posted a photo of himself signing at Emirates Stadium wearing an Arsenal jersey, and wrote: "A new chapter, a new home."
26-year-old Zubimende mainly plays as a midfielder and a central defender. Germany's turnover is worth 60 million euros and the transfer fee is 65 million euros. Last season, he contributed 2 goals and 1 assist for Real Sociedad 48 games.