Representatives for the 22-year-old midfielder have reportedly increased their demands as the deal to bring him to the Premier League was close to being finalised.
Gil flew into Birmingham on Monday to put pen to paper on a five-year contract, with Villa due to hold a press conference at 1pm at their Bodymoor Heath training ground.
That has now been put back, but Gil is still expected to become Paul Lambert’s first January addition as the Scot desperately looks to add some creativity to his squad.
Villa have failed to score in their last four outings but, despite scoring only nine goals in the Premier League all season, sit three points above the relegation zone in 13th.
Gil came through the ranks at Valencia and spent two years on loan at Elche??before returning to the Mestalla at the start of the season.
Villa have also been linked with Manchester City misfit Scott Sinclair having??drawn a blank in 12 of their top flight games this term.