Arsenal are yet to put a foot wrong in the Europa League with two wins from their two group-stage matches but domestically they suffered a painful defeat to newly-promoted Sheffield United last time out.
And after the shambolic display at Bramall Lane on Monday, Emery will take solace in the return of a competition he has won on three previous occasions and made the final with Arsenal last season.
Always a way of bringing the feel-good factor back to a club, supporters have welcomed the blooding of youngsters in the Europa League.
Joe Willock, Gabriel Martinelli, Bukayo Saka and Reiss Nelson have forced their way into Arsenal’s Premier League side based in part on their Thursday night displays - though the latter is now injured.
Yet just as welcome has been the reintegration of injured players. Hector Bellerin, Rob Holding and Kieran Tierney – injured when he signed this summer – all began the 4-0 home win over Standard Liege.
While they were hardly tested by an unambitious Standard side, the trio looked comfortable at the back alongside Shkodran Mustafi – who has been removed from the Premier League side.
But it was the full backs’ displays going forward that truly offered Arsenal fans cause for excitement. Left back Tierney looked able to beat his man and deliver pin-point crosses every time he received possession as he notched an assist for the opener.
Right back Bellerin showed glimpses of his form of last season before, bursting forward on the overlap with purpose and pace to pressure the opposition’s left flank.
Arsenal fans are now calling for Tierney, Bellerin and Holding to be included in Emery’s domestic duties and were disappointed none were selected on Monday evening.
Instead Emery, ever the conservative team selector, chose the same defence that began the narrow win over Bournemouth 15 days previous.
While David Luiz scored and the rest of the backline kept a clean sheet in that match, the limits of those that played are clear to see and were exposed repeatedly against Sheffield United.
Callum Chambers has outperformed expectations at right back since replacing Ainsley Maitland-Niles in the side but is not a natural fit out wide. Sead Kolasinac on the left is suspect defensively and going forward his crossing lacks thought and precision.
In contrast, all evidence suggests Bellerin and Tierney are seamless fits for the position and the long-term options for Arsenal at right and left back.
While Sokratis and Luiz are the senior options, they have hardly formed a reliable centre-back partnership. Sokratis sometimes looks slow and cumbersome while Luiz’s passing has been wayward - and as Chelsea supporters know only too well, is prone to lapses in concentration.
They have managed just one clean sheet in eight Premier League matches and against bottom-side Watford conspired to concede 31 shots on goal – the most Arsenal have allowed since Opta began recording statistics.
Holding was Arsenal’s best defender before suffering his ligament injury around the turn of the year while Chambers won Player of the Season at Fulham last season and delivered a promising display at centre back on the opening day at Newcastle.
Given Arsenal’s leaky domestic defence and the exciting, new-look backline that we’ve seen glimpses of in the Europa League, it’s easy to understand the clamour for Emery to change the entire back four.
For a manager as cautious as Emery, he’ll need some more convincing and it’s hard to imagine him swapping all four. The ostracising of Mesut Ozil, despite Arsenal’s failure to fill the No 10 position, demonstrates just how stubborn he can be.
But Thursday evening, against what should be relatively comfortable opposition, will give Tierney, Bellerin and Holding another audition for the Premier League team.
Another clean sheet and maybe a couple of assists from the full backs will pile the pressure on the Spaniard to make some changes for the visit of Crystal Palace on Sunday.
Emery has been guilty of over-complicating things for his players. At Bramall Lane he rotated through three No 10s and switched formations twice during the match. He has tried and failed to find a solution to Arsenal’s issues in midfield.
The answer in defence looks to be staring him in the face. An impressive display from the ‘Europa League back four’ on Thursday, coupled with Monday night’s problems, may force Emery to take notice.