Liverpool have sent a letter to Fifa asking for special dispensation to sign Argentine midfielder Javier Mascherano on loan from West Ham.
Mascherano has played for West Ham and Corinthians since July
Under Fifa regulations, Mascherano, 22, cannot play for another club this season because he has already represented Corinthians and West Ham.
But Liverpool hope Mascherano will be allowed to complete a move to Anfield.
A Fifa spokesman told BBC Sport that the "player status department" was currently considering the matter.
Mascherano arrived at Upton Park with international team-mate Carlos Tevez on 31 August.
But he has played only six minutes since the defeat at Tottenham on 22 October and is desperate to leave the club.
Under the world governing body's rules, a footballer cannot play competitively for more than two different clubs between 1 July and 30 June the following year.
The rule, article 5.3 of Fifa's Regulations for the Status and Transfer of Players, was introduced in July 2005.
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