Manchester United have told Arsenal that Alessia Russo is “not for sale” at any price after rejecting a second world-record bid of almost £500,000 for the England forward.
The Gunners made their latest offer for the 23-year-old before the transfer deadline of 17:00 GMT on Tuesday.
Arsenal were understood to have eclipsed Barcelona’s £400,000 deal for Keira Walsh with a first bid on Monday.
Euro 2022 winner Russo turned down a contract extension at United in June.
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United, who are top of the Women’s Super League table and three points ahead of third-placed Arsenal, have continued negotiations with Russo but cannot stop their top scorer from talking with other clubs because she has fewer than six months remaining on her deal.
Russo has scored five times in nine WSL appearances this season to take her total to 17 goals in 35 top-flight appearances since joining from North Carolina Tar Heels three years ago.
The former Chelsea development squad captain took her England tally to 10 goals in 17 games by scoring four times to help the Lionesses win Euro 2022 last summer.
Arsenal have a game in hand on United and second-placed Chelsea but have lost forwards Vivianne Miedema and Beth Mead to anterior cruciate ligament injuries this season.