Liverpool will have to apply for permission to include transfer target Victor Valdes in their Premier League squad should they want to play him before January.
The former Barcelona goalkeeper is a target for Reds manager Brendan Rodgers and can complete a move outside the transfer window because he is currently a free agent after his contract at the Camp Nou expired in June.
Liverpool are set to wait for Valdes to return to full fitness before offering him a deal, as he is currently recovering from a torn cruciate knee ligament and is not expected to be fit until October at the earliest.
A Premier League spokesman has told ESPN FC that any club wanting to amend their squad list between transfer windows would have to make an application to do so, which would then be considered on its merits.
Such amendments can only be granted by the league body if a club have room in their squad to include an extra player -- but Liverpool do have space to accommodate Valdes.
The Premier League squad that they submitted to the Premier League on Thursday contains only 19 senior players, with a maximum of 25 allowed.
Of those 19, no fewer than 10 are classified as homegrown under league rules.
Under those rules, a homegrown player is classed as any footballer -- regardless of nationality or age -- who has been registered with a club in England or Wales for three years before the end of the season in which they turned 21.
The Premier League allows up to 17 non-homegrown players in a 25-man squad, and as Liverpool have only nine, there would be plenty of room for Valdes.
UEFA has confirmed to ESPN FC that, should Valdes sign, he will not be able to play for Liverpool in European competition before February.
The Reds have submitted their squad list for the Champions League group stages, without Valdes in it. And a UEFA spokesman has made clear that there is no scope to amend that list outside the transfer window, even to include free agents.
UEFA rules state that, if a club reach the knockout stages of the Champions League or Europa League, they can then -- and only then -- make three changes to the squad they used in the group phase.
Rodgers wants to bring in Valdes to provide extra competition for Simon Mignolet.
The keeper, a graduate of Barcelona's youth setup, first indicated in May 2013 that he was planning to leave the Camp Nou.
He has been out of action since tearing his cruciate knee ligament during a league match against Celta Vigo in March, an injury that kept him out of contention for a place in Spain's World Cup squad.