Here's why you need to win, Man United and Arsenal
WHY UNITED MUST WIN
1 NO MORE TALKING BALLS
If Manchester United lose, Louis van Gaal will invariably talk about his balls again. He will point out the consistency of his long balls and his short balls, their girth and their performance.
And no TV viewer needs to hear or see that, especially when eating supper. More importantly, van Gaal (near right) will start waving a dossier around, handing out bits of paper and generally losing the plot.
The last time he did this was when he handed out copies of Radamel Falcao's United contract.
2 SPARE THE SALIVA
To borrow an old English phrase, the thought of an FA Cup defeat by Arsenal would leave United so angry, they'll be spitting feathers.
And that's the last thing Jonny Evans needs right now. The spitting incident against Newcastle continues to haunt the centre back. Van Gaal has spoken about the need to protect Evans' defence with Daley Blind.
What he really needs is an umbrella.
3 SILENCING LIVERPOOL
With the race for the top four agonisingly close, the FA Cup may separate United and Liverpool this season.
The oldest bauble offers bragging rights between the oldest enemies.
United fans can go out of all the other cups, lose their best players to Barcelona, lose their jobs to a robot, lose their homes to the bank and lose their wives to the karung guni man… but they cannot see Liverpool go further in the FA Cup.
4 REMEMBER THE SUPERSTARS
If United can see off Arsenal, then the entire squad will walk out onto the hallowed Wembley turf in the semi-final.
Supporters may get a chance to see Juan Mata and Radamel Falcao again.
5 THINK OF THE BANDWAGON JUMPERS
Spare a thought for those poor glory seekers who jumped aboard during the final days of Sir Alex Ferguson's reign.
They must think they're on the wrong bandwagon. They must also think that Fifty Shades of Grey is United's fixture list.
WHY ARSENAL MUST WIN
1 BANISH THE NIGHTMARES
Apparently, one or two of the players still toss and turn at night.
The nightmares are horrific. As the sweat pours down their faces, they sit bolt upright and scream: "MONACO!" The Gunners can use the FA Cup to banish those Champions League demons.
The nightmares must stop so the players can sleep again, although they had no trouble sleeping against Monaco.
2 A FREE METALLURGY LESSON
Arsene Wenger refuses to listen to metallurgists.
The Frenchman (near left) still believes that a printed bank balance is a metallic object. He looks at the piece of paper and shouts "trophy" in the way those medieval village idiots barked at the moon.
The FA Cup should remind him that a real trophy has metallic substance. The Gunners can actually see the FA Cup. They can get close to it. They can touch it - all the things they couldn't do with Monaco's midfield.
3 MERTESACKER NEEDS BOOST
After the mangling against Monaco, Per Mertesacker was dropped for the following Arsenal game and needs a desperate career boost.
In terms of maintaining his balance and staying on his feet, the German is right up there with Madonna. The pop star claimed she felt something malfunctioning over her shoulder, something that pulled her out of position.
Gabriel Paulista knows the feeling.
4 JUST THINK ABOUT FELLAINI
Marouane Fellaini is somehow playing regularly for United.
His appearance suggests his head is an animal shelter for stray cats. His most recent girlfriend was a porn star. If he reaches Wembley, then there is no justice in this world.
Having said that, the porn star did give him the elbow just before the upcoming match. The move took Fellaini by surprise. He usually gives people the elbow during a match.
5 GIROUD MUST SCORE AGAINST BIG CLUB
Olivier Giroud is still accused of scoring only against minnows.
The Frenchman can find the net against smaller sides like QPR, but falters when facing the big boys. He needs to prove himself against a top club.
And if Arsenal beat United, he might face one in the semi-final.