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.