The transfer window hasn't opened yet, but the Premier League runners-up have already signed Swiss international Granit Xhaka from Monchengladbach.

Xhaka passed his medical examination last weekend to sign a contract with Arsenal. The Gunners wanted to finalize the deal quickly to avoid Xhaka's price increasing further after Euro 2016. Photo: AFC.

According to the British press, the transfer fee for this deal is around $51 million.

Xhaka arrived in London for a medical examination last weekend. The Swiss playmaker reportedly signed a five-year contract with Arsenal yesterday, reportedly set to earn a lucrative weekly salary of $160,000.

Xhaka will join Arsenal after completing his national duties with the Swiss national team at Euro 2016, which runs from June 10th to July 10th.

"I am proud to join Arsenal," the 41-time Swiss international said after signing his contract. "I am excited to move to Arsenal, fight for this club and play in the Premier League. I will give my all to help Arsenal win trophies and make the fans happy."

Xhaka comes from a family of Kosovar and Albanian origin who immigrated to Switzerland. He is a product of the Basel youth academy, playing for the first team from 2010 to 2012, before being bought by German club Monchengladbach for $9.5 million.

Since last summer, Xhaka, at the age of 22, has been elected captain of Monchengladbach. He led the team to the Champions League, where Monchengladbach earned five points, but still finished last in a tough group with Man City, Juventus, and Sevilla.

Xhaka has long been on Wenger's and Arsenal's radar. The French manager is therefore very pleased to have signed this young star: "Xhaka is a promising talent with good experience playing in both the Champions League and the Bundesliga. I've watched him play for a long time, and now he will add quality to Arsenal."

This is Arsenal's first signing of the summer of 2016, bolstering a midfield that is expected to suffer from a serious shortage of personnel due to the departures of Arteta, Flamini, and Rosicky. With a fee exceeding $50 million, Xhaka is also the first blockbuster signing of the 2016 summer transfer window, promising a lively and expensive transfer window as player prices are expected to fluctuate significantly based on their performances at the Euro 2016 finals in France.

According to VnExpress