The 49-year-old country singer met Sophie Cunningham, coach Stephanie White and Caitlin Clark, and showed off a custom No. 7 Fever jersey.
Cunningham told Shelton she had "lost all focus" before he greeted the team, posed for photos and left ahead of Indiana's second preseason game.
The Fever open against the Dallas Wings on Thursday after beating the New York Liberty 109-91, with Cunningham returning from an MCL tear and Clark coming back from injuries.
With Caitlin Clark back from injury, can the Fever finally capitalize on the hype and become a true championship contender?
Beyond a photo op, how will Blake Shelton's new business deal actually impact the Indiana Fever's future success?
Is a country music venue the key to the multi-billion dollar 'renaissance' planned for downtown Indianapolis?