The fleet-footed attacking midfielder, scorer of the goal that secured the Iberian nation's first world title, tore China apart in Spain's final Euro 2012 warm-up match in Seville last weekend, hitting the crossbar before setting up David Silva to tap in the winner in a 1-0 success.
Iniesta's ability to glide effortlessly past opponents or find a killer pass is perhaps matched only by his Barcelona team mate Lionel Messi and he has developed a fine understanding with Silva that makes the diminutive pair a lethal combination.
"He is in fine shape," Spain coach Vicente del Bosque told a news conference in Gdansk on Friday previewing Sunday's Group C opener against Italy in the Polish port city.
"He is enjoying his football, like all the players, and the doubts we had about his fitness two years ago are absent this year," he added.
"We hope everything goes well and that he will be decisive in the six matches we hope to play here."
Iniesta is likely to operate in his usual position on the left of midfield against the Italians, whom the Spanish eliminated on penalties in Vienna four years ago on their way to winning a second continental title.
Xavi will be pulling the strings in the middle, with Silva probably deployed on the right and Xabi Alonso and Sergio Busquets completing the midfield in central holding roles behind the three playmakers.
"I am in good shape and full of confidence and I feel like I am in optimum playing condition," Iniesta told an earlier news conference at the eye-catching new Gdansk arena.
"It's true that before both the last European Championship and the World Cup I always had a problem and this time it's not the case," added the 28-year-old.
"What I focus on is feeling good and in this case I have achieved that."
Asked if he felt like a leader on the pitch in a vastly experienced team full of European and world champions, he said he was merely focused on doing his job.
"Everyone has to be a leader in their position so that the team performs well as a whole," he added.
Croatia and Ireland complete Group C and the two teams to go through will face the winners and runners-up of a Group D featuring France, England, Sweden and co-hosts Ukraine.
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