Galatasaray have tabled an official 45 million euro offer to Arsenal for one of their stars, according to German journalist Florian Plettenberg.
The "Sky Sport - Germany" reporter says the bid for Brazilian winger Gabriel Martinelli now sits on the desk of Arsenal's board.
Martinelli, he added, has become Galatasaray's top target of the summer window.
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The 25-year-old Brazil international is under contract at Arsenal until 2027, with the option of a further year.
Galatasaray's move fits a wider pattern. This summer, Turkish clubs have chased big names from the Premier League with real intent.
Besiktas got there first, signing Belgian Leandro Trossard from Arsenal earlier in the window for 18 million euros plus two million in add-ons. The 31-year-old brought a three-and-a-half-year spell in London to an end.
Trossard made 174 appearances and scored 36 goals in an Arsenal shirt.
An even bigger name followed, at least in terms of fanbase. Egyptian star Mohamed Salah joined Trabzonspor after closing the book on his Liverpool career.