Both Blaugrana icons have less than a year to run on their current contracts, meaning they are able to discuss terms with other clubs from January onwards. But Bartomeu moved to ease any fears of either player moving on after Tuesday's 3-0 defeat of Juventus in the UEFA Champions League.
"Contracts for Messi and Iniesta? The club members can rest easy," he noted, per Football Espana. "We've already said Messi's renewal is signed and that he'll be at Barca for as long as he wants, the same with Iniesta."
Messi netted twice in the 3-0 win over Juve, continuing his imperious start to the 2017-18 campaign with another dazzling display.
Earlier this month the club president said Messi's father had signed the deal for him in an interview with Ernest Folch and Albert Masnou of Sport, with only the final formalities needed to be fulfilled before Barcelona announce the deal.
After the match against Juventus, Bartomeu was full of praise for Messi, calling him "the best ever." Sports journalist Guillem Balague was also effusive in his acclaim for the Barcelona forward:
Guillem Balague @GuillemBalague
Imagine music without John Lennon. Art without Picasso. Football without Messi. Only three people. But the world would be quite different2017-9-12 21:00:56
It's these types of performances that have had Barcelona supporters a little concerned that the extension has not yet been finalised.
After all, the club has just come out of a summer of major surprises. At the end of the 2016-17 campaign few would have envisaged Barcelona losing Neymar, signing Paulinho and making Ousmane Dembele the second most expensive player in the history of the game.
Losing Messi would be unfathomable for the Catalan outfit. He is arguably more of a talisman than he ever has been for this team.
And as noted by 11tegen11, he continues to link up well with Iniesta in the final third:
More fullback passing than before, but Messi dropping makes for a very strong diamond in midfield. Those Iniesta - Messi arrows! #passmap https://t.co/t1qT9TBT2b2017-9-13 06:53:29
Iniesta's departure may not be as catastrophic as Messi's, although someone so associated with Barcelona's ideals leaving the club would be a blow.
The 33-year-old epitomises what the football club is about having emerged from the La Masia setup and thrived in a possession-based system. And even now, despite being past his absolute best, Iniesta is still an important component in the Barcelona team.
According to Rafael Hernandez, current manager Ernesto Valverde is getting more from the Spain international than his predecessor Luis Enrique:
Rafael Hernández @RafaelH117
Iniesta and Busquets back to their best like it was never their fault like the previous coach "tactics” were to blame 🤔2017-9-12 19:39:46
Despite the reassuring words from Bartomeu there are plenty associated with the Blaugrana who will be sceptical of his comments. After all, as noted by Football Espana, a vote of no confidence against him has been signed by 3,000 of the club's members.
Even so, Bartomeu will surely be aware of just how crucial it is to keep their two legends around beyond this season and would not speak so confidently of their status without reason.