After the recent sale of Cesc Fabregas and the increasing unrest amongst sections of the club's support, Arsenal are under intense pressure to deliver.
Arsene Wenger's depleted squad will need to be at their best against a daring Udinese outfit, capable of exposing their weaknesses.
The game will have enormous implications for the rest of the Gunners' season. Here are six things to watch closely when Champions League football returns to North London.
Aaron Ramsey will be forced to shoulder the burden of providing craft and guile in Arsenal's play. The absence of Jack Wilshere and the potential withdrawal of Tomas Rosicky, increases the responsibility for Ramsey to be at his best.
The young Welshman looked off the pace during saturday's league opener against Newcastle United. Ramsey is being counted on this season to act as the inventive hub in Arsene Wenger's youthful midfield.
Ramsey certainly has the talent to perform this important function. But the extra pressure to produce may be too much to ask of a player still working his way back from a devastating injury.
One of Ramsey's best performances for Arsenal came in the Champions League, away to Olympiakos in late 2009.
He was imperious on the night and ran the game with his accurate and varied range of passing. If Ramsey can replicate this form tonight, he will provide the Gunners with the platform to build a commanding lead heading into the second leg.
Arsenal's defense was the only unit to emerge from the team's listless opening draw with any real credit. It will be important for the central defensive pairing of Thomas Vermaelen and Laurent Koscielny to be just as stout this evening.
Vermaeln delivered an all action performance on Saturday. He was aggressive and committed in the tackle. Vermaelen instilled an intensity in Arsenal's defense that was sorely missed during his lengthy injury layoff last season.
Koscielny was solid and efficient. He displayed his quickness and keen anticipation throughout the game.
While it's true that Newcastle didn't offer a significant threat, Arsenal have been undone by less before. But the Italians will provide a much sterner test.
Not only do they have dangerous forwards like Antonio Di Natale, Udinese also play with more of an attacking mentality than Newcastle.
They like to come forward in waves and at pace. Vermaelen and Koscielny must remain composed and maintain concentration.
They must not fold under the pressure and resort to the kind of rash decision making that has led to many of Arsenal's most costly defensive blunders.
This promises to be a significant night in the career of Kieran Gibbs. The England youth will be charged with corralling dangerous Udinese right wing-back Mauricio Isla.
When Gael Clichy departed for Manchester City, many called on Arsene Wenger to draft in an expensive replacement.
The Gunners' boss has instead opted to keep faith with Gibbs. While he is a big upgrade over Clichy going forward, Gibbs must still prove his defensive capabilities.
Udinese provide a perfect test for the young Arsenal fullback. The Serie A team rely on quick counter attacks from their 3-5-2 base. Their rapid responses are built through the play of their speedy wing-backs.
Chilean international Isla has plenty of tricks and pace. Gibbs will need to maintain concentration for 90 minutes. He cannot afford to take unnecessary risks against Isla, who is capable of producing a dangerous delivery into the box.
If Gibbs can get the better of Isla many Arsenal fans will start to feel more confident that the former Wimbledon prodigy will develop into a fine left-back.
Theo Walcott could be a dangerous weapon against Udinese. But the England speedster needs to rebound from a disappointing cameo at the weekend.
Walcott looked lethargic and clumsy when he entered the fray against Newcastle. It will be interesting to see if he is any sharper tonight.
Walcott can play a key role in exposing the gaps behind Udinese's roving wing backs. If he is an effective threat early on, then Walcott can force Udinese's wing backs to sit deep and take away one of the team's most effective tactics.
The two most important things to watch out for are the timing and frequency of Walcott's runs. If he can get his timing right and sustain his efforts for longer than usual during the course of the game, Walcott should get on the score sheet.
Alex Song will need to work hard to combat the efforts of Udinese's powerful play maker, Kwadwo Asamoah.
The Ghanian international possesses a dangerous combination of strength and flair. He is a clever passer of the ball and is the Italian side's chief source of creativity.
Song will need to be at his robust best and avoid the disciplinary issues and poor technique that have plagued him in the past.
Song must harass Asamoah and disrupt his crisp distribution to Udinese's quick wide players.
With star forward Robin Van Persie serving a suspension, tonight's contest will show how well Arsenal can cope without their influential Dutchman.
It is likely that under performing Moroccan front man Marouane Chamakh will be given another chance to recapture his form.
Chamakh looked dreadful during preseason and will need to do a lot more to convince Arsene Wenger that he still belongs in the squad.
Another option could be to deploy Gervinho through the middle. The Ivorian's excellent off the ball movement along with his strength and pace could be very effective this evening.
Arsene Wenger has even hinted that want away Danish target man Nicklas Bendtner could be given an opportunity to impress.
Given Van Persie's injury history, Arsenal must show that they can function well in his absence. If not, then Arsene Wenger will be forced into the transfer market to bolster his options at striker.
Tonight's contest is a tough fixture. The current mood of many Arsenal fans risks creating an oppressive atmosphere for a team already under intense pressure.
But this game is a perfect opportunity for Arsene Wenger and his players to show they still have the ability to compete at the highest level.
A resolute and composed performance is needed. If the Gunners can take a two-goal lead into the second leg, that will see them through.