The signing of Pierre-Emerick Aubameyang was always a bad omen for Alexandre Lacazette's future at Arsenal.Since leaving Lyon for £42.5 million in the summer, the Frenchman has neither thrived nor flopped at the Emirates Stadium with nine goals in 27 appearances for the Gunners.Nevertheless, the arrival of Aubameyang looked certain to threaten his chances in the first-team for the remainder of the season.Arsene Wenger favoured his record signing up front during the north London derby and when Lacazette was given the chance from the bench, he spurned a brilliant chance to equalise.Even Wenger himself admitted that recent events may have knocked the Frenchman's confidence, speculating: "Maybe the confidence is not at its highest because he has seen a competitor coming in for him."

Lacazette ruled out for 4-6 weeks

On Tuesday, however, things got even worse for the striker with a minor knee operation ruling him out of action for between four and six weeks.

The news came as a blow to the player himself but, given Aubameyang's arrival, didn't appear to pose a great threat to Arsenal. 

Well, that's true for the Premier League perhaps, yet Arsenal fans soon noticed in their droves that Lacazette's lay-out could be terrible news for their Europa League campaign.

It's an even bigger blow when you consider the competition is Arsenal's best chance of qualifying for the Champions League and they may have to contend with the likes of Atletico Madrid and Borussia Dortmund.

The alternative? Danny Welbeck, who hasn't scored more than eight goals in a season since joining the Gunners. Ouch.

Arsenal fans have all made the same point

Take a look at the moment the penny dropped for Gooners:

Eddie Nketiah, anyone?

Arsenal can't call upon Aubameyang given his Champions League appearances for Dortmund earlier this season and it looks unlikely that Lacazette will return for anything short of the quarter-finals.

The Gunners can be at least be reassured by the calibre of opponent they face in the round-of-32 with Ostersund looking unlikely to pose great trouble for Wenger's men.

No matter the opposition, though, Arsenal might have wished they had Olivier Giroud or Theo Walcott to call upon in their all-or-nothing bid for a Champions League return.

Do you think Arsenal will win the Europa League? Have your say in the comments section below.