The 30-year-old custodian backed the decisions made by the 61-year-old coach and alerted his team-mates to the threat posed by Karim Benzema
The 61-year-old had come under fire following his decision to deploy Cesc Fabregas as a false nine in La Roja's 1-1 draw with Italy in their Euro 2012 opener.
Del Bosque was then criticised in the wake of Spain's disappointing display in their 1-0 victory against Croatia, but Valdes has backed the coach's tactical choices.
"I do not understand the criticism targeted at the coach, nor do I share it," he told reporters at a press conference. "In football, things can go better or worse, but the results are there.
"I think the coach has got everything right since he took charge of the national team.
"He is calm and seeing how we are working to prepare for the matches. He wants to protect the group and make sure we keep doing things well and secure the results like we did at World Cup 2010."
Spain will now tackle France in the 2012 quarter-finals, and Valdes stressed that comparing Les Bleus' to Barcelona would be a mistake.
"They have the ambition to have the ball, but to compare them to Barca, that is something I would not do."
Valdes has faced Karim Benzema many times in club matches between Real Madrid and the Blaugrana, and he sent a message of caution to his team-mates regarding the forward.
"He is one of the most dangerous strikers in the world," Valdes added. "That is why he plays where he plays and he does what he does.
"We will have to be very wary of him, Franck Ribery and Samir Nasri, of course."
The 30-year-old custodian was then asked about the reports suggesting that Bayern Munich are looking to install Pep Guardiola as the club's coach in 2013.
"I would be surprised if he takes up another challenge now, since he said he wanted to take a year-long sabbatical from football," Valdes added.
"He would fit in well at any club. No matter where he goes, I would like to wish him the best of luck, unless I have to face his club on the pitch.
"Bayern are one of the greatest clubs in Europe, and he would fit in at any club."