Manchester United and Lyon had both tracked Colombia worldwide Mina, who signed a five-year deal after Barca sanctioned his £27.2 million sale. However after the initial loan Southampton will have an obligation to buy the Englishman for £20 million.
Portuguese midfielder Gomes, 25, will join on a season-long loan at a cost of 2.25 million euros for the English club.
"The manager made me feel confident about playing here".
The fee represents a healthy profit for the Spanish champions, who signed Mina from Palmeiras for €11.8m (£10.6m) only in January and obtained a buy-back option in the deal. However, that has not deterred Everton, who have now secured his signature.
"I have watched the Premier League for a long time. He is a good guy and we want to do our best for Everton". Six months later and after a good World Cup, they have moved him on for nearly three times what they paid for him, despite him never quite performing during his short stay.
Gomes has always been a fringe player at Barcelona, despite signing for a fee of €35 million (£31m/$41m) plus €20m in add-ons in 2016, with only 46 appearances made in La Liga since joining from Valencia.
'They are historically among the four most successful clubs in England and when I found out about the club and what the manager wanted from me, I was happy.
'Marco's words helped me a lot because having a coach who believes in his ideas is important.