Arsenal have confirmed the signing of Mikel Merino from Real Sociedad, with Mikel Arteta saying he is excited by the “experience and versatility” the Spain midfielder will add to his squad. Merino, who had a spell at ­Newcastle earlier in his career, has signed a four-year contract with the option of a fifth year after flying to England to complete his medical last week. The fee is undisclosed but it is understood Arsenal have paid an initial €32.5m (£27.4m), with €5m in add-ons that could take the package to £31.6m. Merino, a No 8 or holding midfielder, was part of Spain’s victorious Euro 2024 squad and is believed to have been tracked by Arteta for some time. “Mikel is a player who will bring us huge quality with his experience and versatility,” he told Arsenal’s website. “He has played at the top of the game at both club and international level for a number of seasons now. Mikel will make our squad significantly stronger, with his technical ability, together with his strong and positive character and personality. “As we all saw in the summer, Mikel is also a winner, with his strong performances throughout the Euros helping Spain win the tournament. We are delighted to welcome Mikel and his family to the club and can’t wait to start working with him.” Arsenal’s sporting director, Edu, said: “This has been another great team effort from many people at the club to finalise the transfer of a player who attracted interest from a number of clubs over the summer. “Mikel was a key target for us this summer, and we identified him as a player who can fit perfectly into our squad and profile to improve us, as we aim to build on our strong ­­performances of last season.” Arsenal have confirmed that Merino, who played alongside ­Arsenal’s captain, Martin Ødegaard, at Real Sociedad, will wear the No 23 shirt. The midfielder Fábio Vieira has joined Porto on a season’s loan. Manchester City’s Portuguese defender João Cancelo has joined Al-Hilal in a €25m (£21.1m) deal.