The black-and-white picture shows Grande sitting on a stage with BTS members Jin, J-Hope, RM, Jimin, V and Jungkook. Suga did not appear in the photo.
"look who i bumped into at rehearsal :)," Grande captioned the post.
The photo fueled some fans' hopes for a Grande-BTS collaboration.
"This pic smells collab," one person wrote.
Grande will perform at the Grammys, where she is nominated for five awards, including Album of the Year for Thank U, Next. She most recently released the live album K Bye for Now (SWT Live) in December.
The Recording Academy announced in a press release Thursday that BTS will perform in the special segment "Old Town Road All-Stars" at the Grammys. The segment features Lil Nas X, Billy Ray Cyrus, Diplo, Mason Ramse and other surprise guests.