Former Brazil midfielder Allan has left Everton to join Al-Wahda on a two-year deal, according to the United Arab Emirates club.
He played 52 Premier League games in his first two seasons but has yet to make an appearance in 2022-23.
Frank Lampard has made several midfield signings, including Idrissa Gueye and Amadou Onana.
UAE Pro League side Al Wahda, who are based in Abu Dhabi, announced the signing on their Twitter feed - although Everton have yet to confirm the move.
Al Wahda are managed by former Swansea City and Sheffield Wednesday manager Carlos Carvalhal, with ex-Leicester City midfielder Adrien Silva among the squad.