The Blues attacker was very pleased with his recall to the national team, and feels the world and European champions put in an entertaining performance versus Panama
The Chelsea star was snubbed for the 2014 World Cup qualifiers against Belarus and France in October, but earned himself a place in national team coach Vicente del Bosque's squad again with his fine performances at club level.
"I was very upset at being left out last time, but it's great to be back with the lads again," Mata was quoted as saying by AS.
The attacking midfielder then went on to express his delight with la Roja's performance against Panama as they cruised to a comfortable win.
"It was not that easy, the game was a potential banana skin," the Stamford Bridge star continued. "They have been doing well recently and have a chance to qualify for the World Cup.
"The conditions weren't the best either [the game was played in 30 degree heat] but we put in a good performance. We played well, we put on a spectacle and we go back to Spain in a very satisfied mood."