The striker, who is his country’s all-time top goalscorer, missed the opening win over Canada with a thigh injury, and has played just 29 minutes of competitive football since August.
Roberto Martinez confirmed that Lukaku is not far away from being available but the Morocco clash has come too soon to start.
“Today Romelu trained with the rest of the group,” Martinez said on Thursday. “It was a control session, now we’ll see how his body reacts now afterwards.
“I don’t think he’ll be ready to start the match against Morocco, but we’ll find out in the next two days.”
Martinez might be tempted to shuffle his pack after the poor display against Canada, with Thomas Meunier a likely candiate to come in for Yannick Carrasco. Amadou Onana is also pushing for a place in the starting lineup.
Morocco are without Bayern Munich left-back Noussair Mazraoui after he was forced off against Croatia with a hip injury, having landed awkwardly. Yahya Attiat-Allah who comes into the side.
Abdessamad Ezzalzoul has a hamstring injury and is misses out, as Morocco look for another positive result having held Croatia to a draw.
Hakim Ziyech had a number of bright moments in that match, particularly in the first-half, and Morocco will rely on the Chelsea winger to cause an ageing Belgium backline problems.
Belgium XI: Courtois; Castagne, Vertonghen, Alderweireld, Meunier; Witsel, Onana; T. Hazard, De Bruyne, E. Hazard, Batshuayi.
Subs: Theate, Faes, Tielemans, Lukaku, Carrasco, Mignolet, Casteels, Mertens, Trossard, Dendoncker, Vanaken, De Ketelaere, Openda, Doku, Debast
Morocco XI: Bounou; Mazraoui, Aguerd, Saiss, Hakimi; Amrabat, Ounahi, Amallah, Ziyech, Boufal; En-Nesyri.
Subs: Hamdallah, Zaroury, Sabiri, Mohamedi, Chair, Aboukhlal, Ezzalzouli, El Yamiq, Dari, Cheddira, Tagnaouti, El Khannouss, Benoun, Attiat-Allah, Jabrane