Brazil midfielder Allan left Everton to join Abu Dhabi-based side Al Wahda for an undisclosed fee on Tuesday.
Allan was allowed to move to the United Arab Emirates Pro League club after falling out of favour with Everton boss Frank Lampard.
The 31-year-old did not play a single minute for the Premier League team this season.
Lampard signed Idrissa Gueye, Amadou Onana and James Garner in the close season to fill Everton's central midfield roles.
Allan signed for Everton from Napoli in 2020 and played 57 games in his first two seasons with the Toffees.
He was able to leave Everton outside the Premier League transfer window as the UAE deadline is not until next week.
"Everton thanks Allan for his service and wishes him all the best for the future," the club in a statement.