Rice, who has now earned 72 caps for England national football team, has been rewarded after another standout season at club level, where he played a key leadership role and helped his side lift the Premier League title. He also received a nomination for the PFA Player of the Year award following a consistent campaign.
Despite speculation around other leaders in the squad, including Jude Bellingham, Tuchel made it clear that Rice sits directly behind Kane in the leadership structure.
Bellingham had recently captained England in Kane's absence during a 1-0 friendly win over New Zealand, but Tuchel's long-term plan places Rice in the deputy role.
Rice has already worn the captain's armband for England on two occasions, including a friendly against Wales in October, showing his growing influence within the group.
Speaking about the decision, Tuchel said: "Er, I think I would say Declan is my vice-captain."
When asked whether Rice had been formally told, Tuchel added: "That is a good question. I was just thinking about it. Whether it is an official thing or not. But I think we had this talk when Harry was not in camp with us. Was it against Wales?"
England will open their World Cup campaign against Croatia on June 17 in Arlington, Texas, with leadership roles now clearly defined as preparations intensify.
