La Roja's World Cup preparations were thrown into disarray when manager Julen Lopetegui was sacked the day before the tournament began after he agreed to become the new Real Madrid boss.
Although Spain went on to win their group under interim manager Fernando Hierro, they were knocked out in the last 16 after losing to hosts Russia on penalties.
"About Luis Enrique, I wish him the best of luck," the 2010 World Cup winner told Sky Sports News.
"Star names are not the most important thing in the national squad of Spain. What we need is to be united.
"Before 2008, there were many difficulties and we had many critics. It was a wake-up call to be united [to be successful] I think that this is something that has been lost.
"I'm well aware of that recent League level and the players levels will result in good things and if all of us want to win, we will be able to do so."
Spain return to action in the UEFA Nations League against England in September.