Iniesta struggled for consistency during the 2016-17 season, but the midfielder has been in excellent form for Barcelona this term.
The 33-year-old will again be a key player for Spain at the 2018 World Cup this summer, and Lopetegui has revealed that he has been delighted with Iniesta's form during the 2017-18 campaign.
"He's better than last year, with more continuity," he told El Partidazo de COPE. "I see him great. He will be with us and he will be willing and committed, like every time he comes with the national team."
Iniesta, who signed a lifetime contract at Barcelona earlier this season, is currently with the Spain squad preparing for Friday's international friendly against world champions Germany.