Roberto was somewhat surprisingly left out of the Spain squad for the 2018 World Cup, despite another impressive campaign for Barcelona.
The 26-year-old was a regular under Enrique during their time together at Camp Nou, however, and is now targeting a return to La Roja ahead of the UEFA Nations League, which gets underway in September.
"Honestly, I thought I was going to get called up," ESPN quotes Roberto as saying. "I wasn't, so that gave me a good chance to have a longer holiday - I was able to watch [the World Cup] on television.
"I have always said that Luis Enrique has been very important in my career, both with Barca B and the first team.
"It's true he's now the Spain coach but I am just focused on giving my best and, if in the end I get the call from Luis, I'll be really happy, but that depends on how I play for Barca."
Roberto has made over 200 first-team appearances for Barcelona since debuting in 2010.