West Ham launched a bid to sign Benfica's £45million-rated striker Darwin Nunez on Sunday as manager David Moyes scrambled for a quality addition to his squad.
Logistics are against them as 22-year-old Nunez is with Uruguay ahead of their World Cup qualifier with Venezuela on Tuesday.
Nunez has scored 20 goals in 25 appearances in all competitions for Benfica this season and has drawn attention from Manchester City, Newcastle and Tottenham in recent months.
Benfica remain in the Champions League and West Ham are wary their bid could be rejected with time running out for Benfica to source a replacement.
Moyes is determined to raise the bar in terms of West Ham's recruitment and is pushing to sign top level players.
He has ruled out moves for the likes of Liverpool defender Nat Phillips while a move for Marseille's Duje Caleta-Car was based on the French side being willing to accept a loan.
Club record bids have been placed in recent weeks, notably with a £50million offer going in for Leeds United's Kalvin Phillips two weeks ago but being rejected.
Leeds have no wish to sell the 26-year-old but know they face a battle to keep him in the summer amid interest from Manchester United among others.
Leeds have been trying to bring in Brenden Aaronson from Red Bull Salzburg but that could be shelved until the summer too which has left them asking for Liverpool midfielder Takumi Minamino on loan, particularly as Crysencio Summerville could join Hamburg today. Leeds also asked about Chelsea's versatile left wing-back Kenedy.