Outgoing Spain boss Vicente del Bosque has revealed that Iker Casillas was "upset" with the national team's coaching staff during their Euro 2016 campaign.

Casillas was demoted to number two goalkeeper at the European Championships as David de Gea was officially appointed number one following a brilliant 2015-16 season with Manchester United.

Del Bosque has insisted that Casillas acted professionally around his teammates, but has suggested that his relationship with the Porto stopper has now broken down.

"I'm sure Casillas was upset with me, and I understand. He never told me that he didn't want to play. With his teammates he was perfect but only so-so with the coaching staff," Del Bosque told El Larguero.

"The only one I didn't send a message [about my departure to] was Casillas. I feel bad that he wasn't happy with the coaching staff. Casillas' anger was only with us. I say this with complete sincerity. He was perfect with his colleagues and I'm sure we'll mend [our relationship] in the future. There can be no grudges.

"Maybe we were wrong in [how we treated] him, I don't know, but he's proud of having played so often for the national team. His CV is not diminished by this. Any coach realises how difficult their role is. We've been together for the past nine years and I have a lot of appreciation [for what he's done]."

Del Bosque revealed on Thursday night that he would be stepping down from his position with the national team after a disappointing Euro 2016 campaign saw them eliminated in the round of 16.