While Arsenal have transformed into genuine title contenders and look as resilient as Manchester United sides of the past, United themselves are no longer the winning machine that they were under Sir Alex Ferguson, lacking in just about every position.
Both sides will be in desperate need of a win when they face off—but for very different reasons.
Following their 5-1 drubbing at the hands of Liverpool, Arsenal need to bounce back in order to stay in the title race and prove that they can handle the glut of tough fixtures coming up. Not only are three points necessary, but a win is expected considering United's awful form.
Do I even need to explain why United need a win? David Moyes might still be under the impression that his side will get back in the mix for the title, but the reality is that they're nine points off of fourth place—let that sink in for a minute.
A loss for United would make a Europa League spot look like a stretch while a win against longtime rivals could give their season a much-needed boost.
With all of that said, the stakes in this match will be as high as ever. Here is a combined XI of Arsenal and Manchester United players, based mostly on form and statistics from this season, although the reputation of players is also taken into account.
Note: Only players who will be available for selection are in the XI, so injured and suspended players like Aaron Ramsey and Mathieu Flamini miss out.
All statistics courtesy of WhoScored.com unless otherwise noted.
Wojciech Szczesny has been one of Arsenal's most improved players this season.
The Pole had an up-and-down 2012-13 campaign, as he was often criticized for his lack of concentration before being dropped from the first team altogether in March. It was this, however, which spurred Szczesny to come back better than ever.
The 23-year-old has really matured in the past six months, virtually eliminating the careless mistakes that used to prevent him from reaching his true potential. Especially in matches where he's not particularly busy, he now keeps his focus and makes crucial saves when called upon.
While David De Gea has been one of Manchester United's better players in their shambolic campaign, Szczesny has arguably been the best goalkeeper in the league this season.
With neither Chris Smalling nor Rafael are putting in convincing performances for Manchester United this season, Bacary Sagna takes this spot comfortably.
Following two leg breaks, Sagna looked like a shadow of his former self in the 2012-13 campaign, but he's returned to form this season and is now a rock at the right side of Arsenal's defense.
It would be a shame if the 30-year-old left for free at the end of the season, like John Cross of Mirror Football suggests, as Sagna has been one of the Gunners' most consistent players since he arrived in 2007.
The transformation of Per Mertesacker from an awkward liability into an elite Premier League defender has been incredible.
He and Laurent Koscielny's partnership has been the foundation of Arsenal's title challenge, as the Gunners boast the second highest amount of clean sheets in the league with 11. What the German lacks in pace, he makes up for with his expert reading of the game and organization.
Manchester United's defense, on the other hand, has been a complete shambles. The likes of Nemanja Vidic and Rio Ferdinand are now shells of their former selves, with neither of the two able to compensate for their lack of speed in the way that Mertesacker has.
If Mertesacker isn't the best centre-back in the league, he's certainly in the top three.
Like I mentioned in the previous slide, the partnership of Mertesacker and Koscielny has been the basis of Arsenal's title bid this season. Before their humiliating loss at Liverpool, Arsenal hadn't lost a game where the two played the full 90 minutes together since January 2012—that's a huge statistic.
Koscielny, like Mertesacker, has come a long way in his Arsenal career, having been a scapegoat in his debut season where he was often prone to lapses in concentration and rash tackles.
Unlike Mertesacker, the Frenchman is one of the quickest defenders in the league and therefore has the ability to catch up with opposing strikers and recover easily.
Arsenal haven't conceded a goal at the Emirates Stadium since Dec. 8, so if the Gunners get a win against Manchester United, it'll likely be due to the defensive work of Koscielny and Mertesacker.
The previous four selections were no-brainers, but this one was really a tossup between Kieran Gibbs and Patrice Evra.
Gibbs has been phenomenal for Arsenal this season, making the left-back position his own, but Evra just edges him out due to his end product in the final third.
That's not to say that Gibbs isn't good going forward—he's often Arsenal's biggest threat down the left wing due to Santi Cazorla frequently cutting in—but Evra has one goal and three assists this season while Gibbs has zero goals and zero assists. Likewise, Evra has completed 30 key passes compared to Gibbs' seven.
According to Squawka, the French international has been Manchester United's second best player this season. While he's not as defensively sound as Gibbs, Evra has been the standout player in an otherwise awful back four.
While Jack Wilshere's season has certainly had its ups and downs, he would still walk into Manchester United's midfield.
In fact, Wilshere is exactly what United's midfield is crying out for. When he's on his game, the Englishman is one of Arsenal's most important players and one of the best midfielders in the country.
Although he hasn't been nearly as prolific as Ramsey, Wilshere is starting to add goals to his game, and his bursting runs from midfield are finally starting to have some end product.
The 22-year-old still has a long way to go before fulfilling his potential, but if he can stay injury-free, then the sky is the limit.
For the purposes of fitting other players in, Wayne Rooney will slot into central midfield, a position that he could certainly do a job in although he usually plays in a more advanced role.
The England international has been one of the silver linings of Manchester United's nightmare season, scoring nine goals and topping the assists charts with nine assists. Without Rooney, United's troubles would be much, much worse.
According to Squawka, the 28-year-old has been Manchester United's best player, and that comes as little surprise. If Moyes' men are to salvage anything from this season, Rooney will be be at the heart of it.
Although it's still strange to see the Spaniard in a Manchester United jersey, Mata is the type of player that's easy to like, no matter what club you support. Soft-spoken and authentic in interviews, Mata was a joy to watch in his two seasons at Chelsea where he terrorized opposing defenses and dominated the midfield.
While the treatment he received from Jose Mourinho means it will take some time before Mata gets back to his best, there's no denying that when on song, the former Chelsea Player of the Year is one of the best playmakers in the Premier League.
While it's true that Mesut Ozil's form has tailed off since starting life at Arsenal so brightly, the knee-jerk criticism aimed at him has been somewhat uncalled for.
After all, his tally of eight assists is the joint most for all Premier League midfielders, while he has the fifth most key passes in the league with 48. That's not too shabby for someone who's playing "badly."
That all being said, there's no denying that Ozil's form can certainly improve, especially when considering what he's capable of. His poorest performances this season have come in the big games, including the 5-1 loss to Liverpool, the 6-3 loss to Manchester City and the 1-0 loss to Manchester United.
With more big matches coming thick and fast for Arsenal, Ozil absolutely must step up his game if the Gunners are to remain in the hunt for silverware.
There are few players in the Premier League that are as technically gifted as Santi Cazorla, and he is without a doubt the most two-footed player in the Premier League; to this day, I'm still not really sure if he's right- or left-footed.
Following a stunning debut season, the Spaniard struggled for form at the start of this campaign due to niggling injuries, but he's finally back in the swing of things—and at the perfect time of year, too.
Cazorla started 2014 in fantastic form, scoring five goals in the month of January while looking like his usual creative self.
He had an off day against Liverpool—the whole team did—but his creativity and energy in midfield could be key to keeping Arsenal's title challenge alive.
This one was a no brainer, really.
Although Olivier Giroud looks like a different animal this season with impressive hold-up play and the ability to set up his teammates, he's still nowhere near the level of Robin van Persie. While Giroud needs three or four chances to score, van Persie can find the back of the net with a half-chance. This, ultimately, is the difference between the two strikers.
The Dutchman's nasty history of injuries has crept back up on him this season, though, as he's made just 14 league appearances. In those games, however, he's managed 10 goals—the same amount Giroud has scored in 23 games.
If Manchester United somehow manage to turn their season around, it will be because of van Persie's goals.