The Toffees completed the signing of Mina on transfer deadline day, with the Premier League outfit said to have paid an initial £27.2m for the centre-back.
Thompson was asked about the move on Sky Sports News, he said: "This guy's made his reputation on scoring one goal against England at the World Cup".
The free signing of Brazilian midfielder Bernard was confirmed after a work permit was granted.
"The English club will pay FC Barcelona 30.25 million euros plus 1.5 million euros in variables". Both the club and the player agreed earlier this summer that a fresh start was needed.
However, Mina failed to impress in just six appearances for Barca since signing from Palmeiras in January.
The 25-year-old has been capped 29 times by Portugal and was part of the squad that won the European Championships in 2016.
Moments later they also confirmed that Portugal global Gomes would join the Premier League side on loan.
"I spoke to Lucas (Digne) and he told me all about the Club, which also made me keen to come here".
Speaking to evertontv, Bernard said that the chance to join a "great club with great tradition" was the key driving factor behind his decision to sign for the club, vowing to help "make things happen" alongside former Watford manager Silva.