Mikel Merino, formerly of Real Sociedad, has agreed to join ARSENAL.

The Gunners will pay £28.4 million up front and a further £4.2 million in add-ons to bring the Spanish midfielder to the club for a total of approximately £32.6 million.

The 28-year-old Merino has been a long-term goal of manager Mikel Arteta’s, and he is now set to sign a four-year contract with an additional year’s option after completing his physical.

After some back-and-forth with Sociedad, Arsenal raised their bid to £25 million, which was their original target for Merino.

However, according to transfer expert David Ornstein, their revised £33 million offer was accepted on Thursday.

After spending £27 million on David Raya and £42 million on Riccardo Calafiori this summer, Arsenal will add this third addition to their total, bringing their total to slightly over £100 million.

The Spain international, who won the Euros, had a year remaining on his contract with Sociedad, and Arteta saw him as an ideal addition to strengthen the midfield.

In the midst of transfer rumours, Sociedad coach Imanol Alguacil deemed it “the best solution,” and Club president Jokin Aperribay was in London to finalise the deal.

Even though Merino was linked to other big European teams, including Juventus, Arsenal remained his preferred option.

In the previous six years, he has appeared 242 times for Real Sociedad and earned 28 caps for La Roja.

Prior to his time at Borussia Dortmund and St. James’ Park, Merino was an apprentice at Osasuna.

The left side of the midfield has been a slight weakness in Arsenal’s build-up after Granit Xhaka left for Bayer Leverkusen and Kai Havertz was found unsuitable to fill the role.

The addition gives the Emirates midfield the depth they lacked at times last season.

Arsenal need to counter Manchester City’s squad depth – as they missed out on the title to Pep Guardiola for the second successive year last season.

From 2018 onwards, Merino had success with Sociedad, where he co-starred with Alexander Isak and Martin Odegaard, two current stars of Prem.

Odegaard, who was on loan from Real Madrid at the time, created nine chances for Merino in the 2019-20 season — the third-most prolific partnership in the side.

The move should be completed in the next 24 hours but Merino is unlikely to be included in the squad to face Aston Villa at Villa Park on Saturday evening.