Isco said he felt “alive” after his first career hat-trick helped Spain thrash Argentina 6-1 at the Wanda Metropolitano Stadium in Madrid.
The Real Madrid playmaker has seen his club football limited in spells under Zinedine Zidane this season.
The Spaniard has played 2,439 minutes in all competitions at club level in 2017/18, with ten players featuring more often.
However, Isco produced a superb display for La Roja against Argentina, whose captain Lionel Messi again watched from the stands because of fitness concerns.
Spain had drawn 1-1 against Germany last week and have now extended their unbeaten run under coach Julen Lopetegui to 18 matches.
“In Madrid I don’t have the confidence a player needs, ” Isco said in a post-match interview, as quoted by Spanish media outlet Marca.
“The matches with the national team give me life. Here I have the confidence of the coach.
“I want to show that I’m a good player. Lopetegui shows me confidence with the minutes he gives me.
“Maybe I’m the problem in Madrid. I don’t know how to win Zidane’s confidence.”
Arsenal, Liverpool and Manchester United have all been linked with Isco previously.