The midfielder admits overcoming Tito Vilanova's absence was emotionally difficult.
Iniesta said: "I'm really proud of this season - all the difficulties we've had to overcome have made it very special. It's not easy to be without your boss for so long , it makes the day to day existence very tough, but we have done our best to get through it. The role of a coach is irreplaceable.
"Whatever he is like, however he talks to you, whatever he's trying to get across, the coach is our leader and at the centre of everything. His opinion is key to marking the way forward. We know we have things to improve and we know that every season it gets more difficult."