The 32-year-old Real Betis midfielder racked up his 88th victory in a Mexico shirt since his 2005 debut, although he said it's taken a strain on him.
"As much as it is a source of pride to be in the national team, after going through various things, the atmosphere in the national team makes you tired mentally," Guardado said in an interview with Fox Sports Mexico. "Sometimes you don't understand the pressure and the criticism, but when you put on the shirt and you're in those 90 minutes representing your country you forget all that and remember why you are here."
The veteran of four World Cups will captain El Tri in the Gold Cup this summer and is expecting a difficult ride, despite Mexico going into the tournament as favorite.
"Those of us who've played the Gold Cup are used to [the expectation] and the responsibility we have to maintain Mexico's prestige in CONCACAF," said Guardado. "The gap has been reduced a lot [between teams] ... things are changing for everyone, but we still have the obligation to be champion."
Guillermo Ochoa, Raul Jimenez and other members of the Gold Cup squad have recently praised Gerardo "Tata" Martino's work in charge of the national team so far, and Guardado feels similarly.
"Before working with Tata, I asked players that had played for him, and I didn't find anyone that talks badly about him," said Guardado. "He understands the human side of the player, and that is sometimes more important than the tactical side."
Mexico kicks off its Gold Cup campaign on Saturday against Cuba in the Rose Bowl, before facing Canada in Denver on June 19 and then rounding off Group A play against Martinique on June 23 in Charlotte.