The Barcelona midfielder rounded off a 2-0 victory over Bolivia on Friday night after Fernando Torres had given La Roja the lead from the penalty spot.
Iniesta says he is confident Vicente del Bosque’s side will be even stronger by the time they kick-off their World Cup campaign against Netherlands on June 13.
“Whether the coach decides to go with those who played tonight or bring in others, the group will be even stronger,” Iniesta told AS.
“We trained well during the week, in every session, and played well today.”
The 30-year-old also revealed that he had to disappoint one of the match officials after he asked for a special memento after the match.
“We only have two shirts each and they were already assigned. They don’t usually ask me, but today one did,” Iniesta explained.
Juan Mata, who was replaced by Iniesta at half-time, spoke of Spain’s strength in depth, highlighting Del Bosque’s options in midfield.
“This team has players of all kinds,” said the Manchester United man.
“We have wide players like Jesus Navas or Gerard Deulofeu and then David Silva, Iniesta and me who like to play inside. That’s the beauty of the national team, it is a group which has so many options.”