Following an incredible first half in the home leg of Arsenal's Europa League quarter final match-up with CSKA Moscow, they find themselves 4-1 up on aggregate going into the second leg.It's undoubtedly a good position - but still, this is a fixture that needs to be approached with a fixed game plan and a sense of trepidation. Having a good foothold in the first leg does not guarantee progression - as was the case in the ties against Ostersund in the Round of 32 of this competition, where the Gunners scraped by the Swedish minnows by the skin of their teeth despite an excellent first leg. There's also the undoubtedly notable aspect of the game taking place in Moscow. It is a trip that English teams have struggled with in the past, with a combination of a hostile atmosphere and one of the longest trip in European football playing a part in this.Viktor Goncharenko's side came to play football in North London - their was no sitting back, straight from the off. it was an admirable approach - and one that seen them get an away goal on the board thanks to a stunning free-kick from Aleksandr Golovin - but one that sees them with an uphill battle at home.The first half in the home leg was genuinely one of Arsenal's best halves of the season, if not the best. While the defensive frailties that have been so apparent throughout the season remained, the offensive play was some of the best that was seen in recent seasons - perhaps reaching a climax with Aaron Ramsey's incredible looped flick for the third goal.Following on with more high praise, the game represented Alexandre Lacazette's best so far in an Arsenal shirt, in my opinion. The french striker who arrived from Lyon in the Summer scored a penalty to help Arsenal regain the lead at 1-1 and followed that up with the last goal of the game, a fine poachers finish.After having a hard time upon occasion this season and just returning from a knee injury that had sidelined him for several weeks, it was a very positive performance from Lacazette, and with Pierre Emerick Aubameyang cup-tied for the Europa League, his role for the remainder of the competition may be a vital one.Also in contention to feature - certainly at some point, if not from the start - in this game is Danny Welbeck - fresh off scoring his own brace against Southampton at the weekend. Another player who has had a frustrating time this season, he will be hoping to build upon his recent good performances and add more goals to his game. Whoever Wenger opts for up-top, he at least has options.One feels that if Arsenal are to score a goal at the VEB Arena on Thursday evening, it may be to difficult of a route for CSKA Moscow to come back from. From the previous game - and indeed their long stay in Europe this season thus far - we are aware that they pose an attacking threat. In the previous leg, after losing to Lyon at home in the first leg, they came back and won the tie 3-2 in Lyon to progress to the quarter finals.Early on in the first leg against Arsenal it looked certain that Ahmed Musa - currently on-loan from Leicester City - would use his intense pace to make himself a nuisance for Arsenal's defenders and Goncharenko will be optimistic of the Nigerian forward finding the net in the second leg. In contrast to Arsenal's winning run of 6 matches, CSKA suffered another defeat over the weekend, this time to city rivals Dinamo Moscow.The result leaves the side eight points adrift of Russian Premier League leaders Lokomotiv Moscow. In team news, Henrikh Mkhitaryan, who damaged his medial knee ligament in the first leg is expected to miss the rest of the season. This will be a real miss for Arsene Wenger's side - especially in Europe, where has been particularly excellent since joining from Manchester United in January. The only way, it would appear, that the Armenian could potentially play for Arsenal again this campaign is if they were to make the final of the Europa League.Expected to take his position is the aforementioned Welbeck. In goal, Petr Cech will retain his position in goals for this cup tie as David ospina, who injured himself just prior to the first leg, is still out.After being rested over the weekend, Laurent Koscielny, Nacho Monreal, Ramsey, Jack Wilshere, and Lacazette will all be expected to start. It is likely the team will line-up in a 4-2-3-1 position with Lacazette leading the line and Welbeck-Ozil-Ramsey occupying the positions behind him.For CSKA, Kirill Nababkin could return after missing the first leg through suspension. Viktor Vasin and Astemir Gordyushenko will be sidelined until the summer with knee ligament injuries. Mario Fernandes could just miss out through a hamstring problem.Thursday nights fixture will be an interesting watch, and there are plenty more fascinating ties across the other Europa League match-ups. It looks likely that Atletico Madrid and Lazio will be in the semi-final draw as they take two-goal advantages into the second legs of their ties against Sporting Lisbon and Red Bull Salzburg respectively. The other tie in the competition is more closely ran, as Red Bull Leipzeig take a 1-0 advantage to Marseille. However the ties play out, there will be some top teams playing in the semi-finals. Arsenal make the trip to Moscow and the VEB Arena to face CSKA Moscow in the second leg of their Europa League quarter final match-up on Thursday the 12th of April, with kick-off scheduled for five past eight British time.