Ziyech in Morocco squad despite lack of game time at Chelsea
Ziyech has started only twice for Chelsea this season but is one of nine players who return for a second successive World Cup after being included in the squad in Russia four years ago, where Morocco were eliminated in the group stage.
Ziyech had been the subject of a dispute between the Moroccan federation and previous coach Vahid Halilhodzic after the Chelsea winger and Bayern Munich defender Noussair Mazraoui (24) were left out for disciplinary reasons last year.
Halilhodzic resisted calls by FA chief Fouzi Lekjaa to restore them to the squad and was subsequently dismissed in August with former Morocco international Regragui named his successor after he won the African Champions League with Wydad Casablanca in May.
Regragui also kept faith with West Ham defender Nayef Aguerd (26), who missed the first three months of the season with an ankle injury, and Sevilla striker Youssef En-Nesyri (25), who has also struggled this season.
There was a surprise call-up for uncapped Belgian-born teenage midfielder Bilal El Khannous (18), who has helped Racing Genk to a runaway lead in Belgium this season, and Serie B club Bari striker Walid Cheddira (24), who is Italian-born but made his debut for Morocco in September.
Morocco compete in Group F at the World Cup against Belgium, Canada and Croatia.
Morocco Squad
Goalkeepers
Yassine Bounou (Sevilla)
Munir El Kajoui (Al Wehda)
Ahmed Reda Tagnaouti (Wydad Casablanca)
Defenders
Nayef Aguerd (West Ham United)
Yahia Attiat Allah (Wydad Casablanca)
Badr Benoun (Qatar SC)
Achraf Dari (Stade Brest)
Jawad El Yamiq (Real Valladolid)
Achraf Hakimi (Paris St Germain)
Noussair Mazraoui (Bayern Munich)
Romain Saiss (Besiktas)
Midfielders
Sofyan Amrabat (Fiorentina)
Selim Amallah (Standard Liege)
Bilal El Khannous (Racing Genk)
Yahya Jabrane (Wydad Casablanca)
Azzedine Ounahi (Angers)
Abdelhamid Sabiri (Sampdoria)
Forwards
Zakaria Aboukhlal (Toulouse)
Sofiane Boufal (Angers)
Ilias Chair (Queens Park Rangers)
Walid Cheddira (Bari)
Youssef En-Nesyri (Sevilla)
Abde Ezzalzouli (Osasuna)
Abderrazak Hamdallah (Al Ittihad)
Amine Harit (Olympique Marseille)
Hakim Ziyech (Chelsea)