4 Things We Learned as Manchester United Cruised Past Arsenal Into FA Cup Fifth Round

Manchester United progressed to the fifth round of the FA Cup, as they beat Arsenal 3-1 on Friday evening.

The Red Devils won thanks to goals from Alexis Sanchez, Jesse Lingard and Anthony Martial in a convincing win at the Emirates, with Pierre-Emerick Aubameyang scoring Arsenal's consolation.

United will now wait to see who they draw in the next round when the draw is made on Monday night. Arsenal now have one less competition to worry about, meaning that they can focus on the Premier League and Europa League.

1. Manchester United Are Back

Under Ole Gunnar Solskjaer, Manchester United have now won all eight games in three competitions. They are truly flourishing under their caretaker manager, and in case they hadn't proved themselves in their previous seven consecutive wins, they definitely did so on Friday.

The Red Devils were fantastic at the Emirates, outclassing their opponents in an excellent performance once again. Despite their perfect form, United have failed to get full recognition with recent wins, with the supposed low quality of their opponents used as an excuse. 

However now that they have defeated Tottenham and Arsenal it is hard to doubt them or lambast them, as Solskjaer has revitalised United. Everything is going perfectly at Old Trafford, as they continue their revitalisation to the old days of Sir Alex Ferguson.

2. Arsenal Desperately Need Defensive Reinforcements

Arsenal were far from their best on Friday, conceding three goals at home for the first time this season. Unai Emery's defence evidently had gaps which United capitalised on, something which clearly showed as they conceded twice in two minutes in the first half.

However their defensive situation is made even worse by their injury problems. Centre-backs Sokratis Papastathopoulos and Laurent Koscielny both went off injured on Friday, with Rob Holding and Hector Bellerin also sidelined for the rest of the season.

With Arsenal's defensive options heavily limited and less than a week of the January transfer window left, Emery needs to take action as soon as possible. If Arsenal don't address their defensive crisis they will surely struggle in this crucial second half of the season.

3. Ainsley Maitland-Niles Can Flourish in Bellerin’s Absence

With Hector Bellerin ruled out for the rest of the season with a cruciate ligament injury, Ainsley Maitland-Niles was given a big opportunity against Manchester United as he filled in at right-back.

At 21 years old, Maitland-Niles looked so mature and experienced, and was Arsenal's standout player in a disappointing defeat. The fact that he is able to keep experienced Swiss veteran Stephan Lichtsteiner out of Emery's lineup is something to take note of.

With Bellerin out for the rest of the season and Lichtsteiner seemingly out of favour, this could be a huge opportunity for Maitland-Niles. Hopefully he will be able to further prove himself, as the youngster looks to establish himself in the Arsenal lineup. 

4. Romelu Lukaku Can Contribute More Than Just Goals

Romelu Lukaku was United's man of the match at the Emirates, yet he didn't find the back of the net. Instead the Red Devils striker got two assists and was crucial in every attack, at the heart of every move.

Lukaku showed that his nine goals this season are not all he has to offer to Solskjaer. Having registered just two assists all season before Friday's win, Lukaku doubled his assist tally in one night as he did very well to set up Alexis Sanchez and Jesse Lingard.

It was a great sight for United fans to see that their striker can do more than score goals, and is able to help his team. Lukaku had an outstanding game at the Emirates, and will hope to continue his assisting form over the next couple of months.