The striker missed Saturday’s 2-0 win against Perth Glory after being rested following his absence from training the previous day.
He had been expected to feature against the Championship side and Ole Gunnar Solskjaer stated Lukaku would play a part during his pre-match press conference.
However, Lukaku he was not named in the squad despite arriving at the Optus stadium with the rest of the team with Solskjaer claiming he had a ‘knock’, while stopper David de Gea also missed out with injury.
The news will only add fuel over Lukaku’s future with the club.
Inter Milan have been strongly linked with a move for the forward, with new San Siro boss Antonio Conte a reported admirer of the frontman.
Lukaku revealed after Saturday’s game that there would be updates on his future this week but is is believed Inter Milan are still short of United’s £75m valuation of the forward.
Officials from the Serie A club met with United representatives in London last week and they’re likely to firm up their interest with an official bid this week.
Solskjaer admitted yesterday that Lukaku’s departure could force him to change his transfer plans this summer as he’ll need to make further additions to his squad. “If we sell players we will have to replace them,” said the Norwegian.