The encouragement given to Olivier Giroud last week by his late equalizer at Everton counts for nothing now, with the France forward ruled out until the new year.
Any pretense that Wenger might have had about Yaya Sanogo leading the line in his compatriot's absence, meanwhile, can now be given up.
He remains a work in progress and that landmark performance - that great vindicator - does not look forthcoming. He will grow better in time but now he is learning his trade. With the Premier League and Champions League to be contested and Arsenal in a most difficult European group, Wenger cannot afford to have an apprentice forward learning on the job.
MORE: Alex Morgan upset at 159-degree temps | Transfer photos
Arsenal created more than 20 chances at the King Power Stadium and played, for the most part, in the Leicester City half, but with Sanogo at the sharp end of the attacks, the efforts were in vain.
He had one opportunity to demonstrate to his manager that he was capable of deputizing for Giroud and that came in the second half. Chances do not come easily against Leicester, so well drilled is that team with Wes Morgan outstanding in the center of defense, and when they do arrive, they must be snaffled up.
Sanogo, left one-on-one with Kasper Schmeichel, could only find the reach of the Dane. Arsenal had plenty of the ball but could not do anything productive with it. Schmeichel was not overworked while Morgan and the emerging talent Liam Moore remained in control.
Arsenal's play was mostly in front of that duo with their abundance of playmakers struggling to find adequate movement from the man ahead of them. Even the goal the team managed came courtesy of a poor touch from the 21-year-old. He could not quite read the lofted pass of Santi Cazorla and could only prod the ball towards goal. Alexis Sanchez then tidied up the rebound.
Contrast that to Leonado Ulloa at the other end. Granted he should have done better with a clear-cut second-half chance but his display had everything that Sanogo's did not.
He was sought as the line leader and often brought his colleagues into the game. His movement was purposeful and he always has goals on his mind. A better header than the one he scored to equalize would be hard located.
Arsenal has a little over 24 hours to move in the transfer market. Giroud is out until the next one opens. It would be negligent for Wenger to move into the crucial autumn months with Sanogo as his first-choice striker.
What Arsenal needs is a forward up there the team can trust. The Gunners need a player who demands the ball and guarantees danger with it at his feet. They need, in truth, someone like Diego Costa.
Wenger says Arsenal is "very active" with hours remaining in the transfer window and Goal understands Carlos Bacca, the Sevilla forward, is the latest subject of the Gunners' advances. A relatively modest fee of 16 million euros should be enough to pull him from Spain.
He is a proven goalscorer domestically and in Europe and would appear to fit the bill due to his work rate and instincts.
Arsenal fans were left waiting a long time for superstar signings before Mesut Ozil and Alexis Sanchez were purchased at significant expense.
They were bought to load the bullets into the chamber, but Arsenal still need someone to fire them.