Enrique named a 23-man squad for the two games on Thursday, before facing the press to explain his decisions.
"Four players are missing through injury. We've tried to put together a squad that will be able to compete in the games against Wales and England," Enrique explained.
Regarding the absence of Diego Costa, Enrique said: "If he's injured, he's no longer of interest. It's the first time I've had to deal with injuries [as Spain boss], when I see such a situation it makes me sad, but I also recognise the opportunity it gives to other players. It increases the competition for places and keeps everyone on their toes.
"I've just seen Joaquín's video. He's playing really well for Betis. I'm sure that we'd all have more fun if he were here," the Spain boss joked.
The topic of conversation soon turned to Alba, with rumours having surfaced of a bust-up between the full-back and Enrique during their time at the Camp Nou after he was left out of the squad during the last international break.
The Asturian was in no mood for such talk, though, saying: "I don't tend to talk about players who have not been called up.
"I can justify it however I want. Azpilicueta plays at full-back for Chelsea and Jonny is right-footed. He's been playing on the wrong side but whenever Hugo Mallo has been injured he's played on the right. I don't care, I can give whatever reason I want. As Spain manager I have the right to choose whichever Spanish player I see fit."
Two other interesting names included were those of Atletico Madrid midfielder Rodri, often compared to Sergio Busquets, and Borussia Dortmund loanee Paco Alcacer, with Enrique saying of their inclusion: "Rodri has a great point of reference in a unique player such as Busquets. He [Busquets] still has plenty of football ahead of him but rodri could match him or even better him.
"I know Paco Alcacer very well. He's playing very well for Borussia Dortmund and I'm delighted to have him with us."
Despite the fresh faces, one big-name star will certainly miss out, with Isco sidelined by injury. "It's difficult to deal with Isco's injury. He's a match winner. But we have similar players who can fulfil the same role in the team.
"The door to the national team is open"
"Koke is a very important player for his club, just as he is and has been for the national team. I'm open to players surprising me. The door is open for every player and I consider Koke to be ready to help us right now," Enrique said of the Atletico Madrid midfielder, who was not included in his first squad.
"Unfortunately I can only take 23 players, but I'm the one who makes that decision. I'm sure there are another 23 who are performing and competing well but who aren't in the squad," the 'La Roja' boss continued.
"I've never left a player out for personal reasons, always for sporting ones. From the beginning I've said that there are top-level players who will miss out and that may be unfair, but there is only space for 23 players in the squad.
"We'll evaluate each player's workload. The friendly will give me an opportunity to try out players and things that take my fancy."