With the league looking like more and more of a foregone conclusion than ever due to the incredible dominance of Manchester City, this fixture on Friday night has taken on a different importance - it may very well be the most important Premier League fixture of Arsenal's season.In late August, when the league was young and things were going okay, Arsenal went to Anfield and got humiliated 4-0 by a Liverpool team that showed up the ineptitude's of a team that didn't look like it knew what was happening - in many ways it didn't, with Alexis Sanchez's future still very much uncertain when the game was being played - things off the pitch haven't changed very much. It was hands-down Arsene Wenger's sides worst game of the season, and thankfully, regardless of how pessimistic you are, it's hard not to agree that things on the pitch have improved.Friday's night fixture give the Frenchman a change to right some wrongs against Jurgen Klopp's men with the home-comforts of the Emirates potentially providing a slight advantage - but Liverpool have been in nothing short of tremendous attacking form in all competitions.The new "fab four" of Phillipe Coutinho, Roberto Firmino, Sadio Mane and Mohammed Salah is the most threatening attack force in the league - possibly even in Europe - and they will be out to continue their pressure on the top 4.Liverpool currently sit one point ahead of Arsenal in 4th place, meaning that if this game produces a winner, they're guaranteed to go into Christmas in a Champions League position. Liverpool did not have to contest a midweek league cup fixture this week as they were knocked out in the previous round by Leicester City, meaning that they may have a couple of days of freshness on some of the Gunners depending on Wenger's team selection.This fixture is expected to be the return of Alex Oxlade-Chamberlain to the Emirates, with his final game club coming in hindsight quite amusingly against Liverpool in the 5-0 drubbing and his first game following his £35 Million move for his new club also ending 5-0 against Manchester City, with him once again on the losing side. While his time at Anfield has started slowly, the Englishman is beginning to see some first team action and was awarded the Sky Man of the Match award for his performance in his side's 4-0 defeat of Bournemouth - with his manager hailing "his unbelievable potential", noting that he has "so much left to show still".The last time Liverpool would have been this intimidating to come up against would have been when Luis Suarez was in his pomp during the second half of the 2014 season - and due to the sheer amount of attacking ferocity available to the reds, they may genuinely be an even more frightening preposition this time around.Where they fall down, however, as has been the case for several years at this stage, is in defence. Klopp's arrival may have brought the Gegenpressing for which he became renowned to the excitement of those in Merseyside, but the one niggling vital downfall is at the back - and what Wenger and Arsenal will be hoping to expose.Simon Mignolet is somehow still marshaling the net for Liverpool, with a likely pairing of Ragnar Klaven and Dejan Lovren at centre-back, following their display against Bournemouth - not the most intimidating defense in the league, and certainly not the most in the top-6.Arsenal will also be hoping to exploit the relatively inexperienced full-backs of Andrew Robertson and Jo Gomez, both likely to begin as well following the weekends match. Width will be important in this match, and thankfully, it's an area where the Gunners are strong, with Iwobi and Sanchez doing a fine job of drawing the play to the flanks over the past few league matches.In terms of injuries, Arsenal will be missing Aaron Ramsey - who is expected to return at the beginning of January - and Olivier Giroud who went off late-on in the League Cup match against West Ham United on Tuesday night, and while the extent of his injuries are unclear, he will not be featuring on Friday. Returning, however, is Shkrodan Mustafi, giving extra options at centre back, meaning there may be a shake-up of the Laurent Koscielny and Nacho Monreal's partnership that has featured in recent games. Midfielder Francis Coquelin, who also went off late-on in the Cup following a challenge from Andy Carroll, is also available for selection after his knock was deemed to be a cramp.In terms of the away side's personnel, Liverpool will be missing Daniel Sturridge (ill), as well as full-backs Nathaniel Clyne and Alberto Moreno who are both out with injuries. Joel Matip has returned to training following an absence and a decision will be made on his fitness before the game, meaning the defender may have a part to play in North London.It is likely that Adam Lallana will be rested at the beginning of the game, with Klopp noting that he is still only easing back into the first-team following injury and does not want to push him too far, too fast. In his place, however, will be the very capable Mane who was rested against Bournemouth. With goals in his last 3 games against the Gunners, he certainly is a threat to watch out for. Amidst a flurry of January transfer gossip about both sides star players, these are two uncertain teams, and every point is going to be integral in securing Champions League football for next season. Arsenal have won 13 of the last 14 home matches in the Premier League - the exception being Manchester United at the beginning of this month - and will be looking to continue this rich vein of form in what is an undoubtedly tough fixture that will give the winner a psychological advantage half way through the season - this is a real six pointer.This one's not to be missed - Arsenal play Liverpool on Friday the 22nd of December in the Premier League at the Emirates Stadium, with kick-off at 7.45pm.