The Champions League winner, now 32, left Liverpool two years ago for Al-Ittihad.
Still with the Saudi Pro League giants, Fabinho was recalled to the Brazil squad by Ancelotti for this past week's international friendlies.
"I want to find a profile that fits Casemiro's characteristics," explained Ancelotti. "We have very good midfielders, but with different defensive profiles, and that's why we called up Fabinho.
"He has the characteristics, the structure, the knowledge of the position and the experience. He is a player who is currently playing and has already played at a very high level in Europe."
The midfielder saw action in this week's 1-1 draw with Tunisia as a second-half substitute.
