With a little less than two hours left for Premier League sides to do deals, Everton are cutting it close but they remain confident of taking both deals over the line in time.
The fee for Mina, who only joined the Spanish champions in January, could rise by €1.5 million and Barcelona have inserted a buy-back clause in the player's contract.
But Tottenham Hotspur ended the window as the only club not to bring in a new player while Manchester United were unable to bring in the central defender they were reported to be keen to recruit.
Mina, who impressed at this summer's World Cup, had emerged as one of Jose Mourinho's key targets ahead of deadline day, with moves for Toby Alderweireld, Harry Maguire and Jerome Boateng also having been touted.
Everton signings Yerry Mina and Andre Gomes.
Mina, who was in the sights of Manchester United and Paris Saint-Germain, has signed a five-year deal for a fee potentially rising to €31.75milllion.
'I have watched the Premier League for a long time. This is a great opportunity for me and I am looking forward to competing here.