Iniesta announced at an emotional press conference on Friday that this will be his last campaign in Catalonia ahead of an expected move to the Chinese Super League later this year.
Having already twice broken the club's transfer record over the past year to sign Ousmane Dembele and then Philippe Coutinho, Valverde concedes that nobody can quite match the qualities of his departing star talent.
"We had spoken before but those things are private issues between the player and the coach," he told reporters when asked about Iniesta's decision to quit. "Let's not kid ourselves, Iniesta is a player that can't be replaced.
"He is a player with characteristics that mean you can't really think about anybody else doing something similar. That's the fact. When you've got a player of that level who leaves a team you have to find other balances in the team, different ways.
"We know Barca has a very set style of football, it is very clear how we play. But what Iniesta gives you, you're not going to get from any other player."
Iniesta can win La Liga for a ninth time on Sunday if Barcelona earn a point against Deportivo La Coruna.