That is the view of ESPN FC pundit and former Liverpool defender Steve Nicol.
Ibrahimovic is set to return to action after Christmas following the knee injury he suffered in April.
Lukaku started his Manchester United career in fine form, scoring 11 times in his first 10 games.
However, he is now on a run of seven appearances without a goal for the Red Devils.
Lukaku could have had a chance of ending that in the Champions League clash with Benfica, but Anthony Martial was chosen to take a penalty instead.
Nicol says the fact Mourinho does not trust Lukaku with penalties shows he will be dropped when Zlatan Ibrahimovic is fit.
“Listen, if he’s not going to let him take a penalty after spending £80million on him, and he’s not scoring goals, you think he’s going to play him over Ibrahimovic?” Nicol asked.
“I don’t think so.”
Nicol’s ESPN colleague and former Chelsea midfielder Craig Burley agrees.
He says Jose Mourinho will not be sentimental in his selection despite spending mega money on Lukaku in the summer.
“Yes (Lukaku will get dropped),” Burley said.
“He’s got another guy there he can play, Marcus Rashford. He needs to get results, not sentiment.”
