Brazilian-born Costa featured in two friendlies for the Selecao earlier in the year, but has been included in Vicente del Bosque's squad for the games with Equitorial Guinea and South Africa after having declared his intentions to play for his country of residence as opposed to birth.
As well as Costa and Villa, Atleti duo Juanfran and Koke were included in Del Bosque's squad for the friendlies, with the likes of Adrian Lopez and Mario Suarez having previously been capped, and Villa is confident Atletico's strong start to the season will pave the way for more team-mates to earn a place at the World Cup.
"Let's hope even more Atleti players get called – the more [Atletico players] at the World Cup, the better," he said at the draw for the fourth round of the Copa del Rey.
Holders Atletico have been drawn against Sant Andreu in the tournament and Villa has urged Diego Simeone's side to show their credentials for retaining the trophy from the outset this season.
"Atletico have to show why we won the competition last season and we need to do that right from day one," he added.
"Of course we need to be humble but we believe that we can retain the trophy."