Tranmere are trying to sign Liverpool misfit Phil Babb on loan in time to play in their Worthington Cup semi-final second leg next week.
Rovers boss John Aldridge, a one-time international playing colleague of the Republic of Ireland defender, faces a major defensive crisis ahead of the second leg of the tie with Bolton next week.
Now he wants to draft Babb into the side, and has been given the go-ahead from Liverpool.
The Nationwide League confirm that there is no rule in the competition that prohibits the signing of a loan player half way through a two legged semi-final.
A league spokesman said: "The only rule states that the player's original club must give their permission for him to play."
Babb, who has not played a senior game for Liverpool this season, is therefore not cup tied. Aldridge must now persuade the player to make the switch for a month.
Babb's Liverpool contract runs out in the summer, and it is expected he will leave under the Bosman ruling for nothing, and move abroad where Real Sociedad in Spain are believed to be his likely next club.