Chelsea midfielder Juan Mata says that he has never lost faith in his ability, despite being regularly left out of the team this season.
Mata, 25, has started only four Premier League games since manager Jose Mourinho returned in the summer.
In an interview with the BBC's Football Focus, Mata said: "The manager doesn't have to explain why one player is playing or not playing.
"I never lose faith, I believe in myself, I know what I can do."
Mata was Chelsea's player of the season last year, scoring 20 goals in 64 appearances, but has rarely been selected by Mourinho this term.
He was left out of the Spain squad for World Cup qualifiers in September, but was
"It's important to have a good season and I have faith that I am going to be in Brazil," he said.
"Since I've been with the national squad there has always been a lot of competition for places and I have been lucky enough to be at the World Cup, the Euros and the Confederations Cup.
"I will fight to be there, it would be amazing for me to be at the World Cup in Brazil.
"It is a country where they love football, you can feel it if you are there. I have confidence that I will be there because it's what I want. It will be difficult to win it again but we will try."
Mourinho has steered Chelsea to second place in the Premier League table since returning from Real Madrid, and Mata praised the Blues manager's impact on the squad.
He said: "He has brought a winning mentality. Every time before training or whatever game he is really focused mentally about the way we face games.
"I think this is really important because confidence is important in life and in football as well."
Watch the full interview on Football Focus on BBC One and the BBC Sport website from 12:00 GMT on Saturday.