The Blaugrana announced in July that Messi had agreed to a contract until 2021, with his previous deal due to expire in 2018.
While a formal deal signing was expected to soon follow, the Argentina star is still yet to put pen to paper, leading to speculation over the 30-year-old's future.
Spain midfielder Iniesta, meanwhile, is also out of contract next year and has remained coy over whether he will sign a new deal at the club where he spent his entire senior career.
When asked about Messi's contract renewal, Fernandez told Movistar: "I point to our president's words. [The signing] is an act which could happen at any moment. I hope it's soon."
Speaking about Iniesta's situation, he added: "What we want is that Andres is here for many more years and that he ends his career here. I'm convinced that will happen."