The Everton youngster was not used at the weekend despite a change of manager.
The 20-year-old has that in abundance, and after his impressive showings at the U20 World Cup he was expected to play a major role at Goodison Park this season.
However, Koeman failed to give Lookman a run out of any kind until 15 minutes from the end of what turned out to be his last game in charge, and by then the damage had been done.
With David Unsworth taking caretaker charge, the inclusion of Lookman in Everton's starting line-up was expected to be one of his first decisions, and yet when the Toffees took to the field against Leicester City on Sunday, the youngster was again on the bench.
While the return of Kevin Mirallas and Aaron Lennon signaled a clear change of thinking, Lookman did not get even the briefest opportunity to prove his worth, so is he actually ready for Premier League football?
It certainly seemed so when he scored on his debut against Manchester City last season, but that is as good as it has got so far, at least at club level, and if Unsworth followed Koeman's lead in not putting his faith in Lookman, one wonders what the next few months have in store.
There is no doubt that in time the winger will be a regular for Everton, but it seems two managers in a row have felt he is not yet ready for regular top flight action, with the cup competitions his best and possibly only real chance to impress for a while yet.