The transfer was confirmed earlier this month via Al-Shabab's official Twitter account, with the 31-year old agreeing a three year deal with Luis Garcia Plaza's side ahead of the 2020-21 campaign.
Banega has made over 200 appearances in all competitions across to spells with the Andalucian club, firstly between 2014 and 2016, before returning to the Estadio Ramon Sanchez Pizjuan in 2017, after an unsuccessful season with Serie A side Inter.
Despite the ongoing rumours of his anticipated summer departure from the club, he has remained a key player for boss Julen Lopetegui so far this starting 20 of their 22 La Liga games so far this season.
“I was not disappointed with the news, in fact quite the opposite,” Monchi is cited as saying by Marca.
“We handled all details of the exit and everyone is satisfied with how it has been conducted”.