Phil Jones limping off the pitch at Old Trafford on Monday night, and then subsequently leaving the stadium in a fragile condition, was one of the last things Sir Alex Ferguson will have wanted to witness.
His Manchester United side overcame a stubborn and impressive Reading side to advance to the quarterfinals of the FA Cup, but just how much of an issue does his jack-of-all-trades' ankle knock provide?
Let's take a look at Man United's options for the UEFA Champions League Round of 16 second leg against Real Madrid without him.
What Jones did against Madrid
Phil Jones is a versatile player. We knew this from his time at Blackburn Rovers, where he played centre-back, holding midfield and a box-to-box explosive role.
At United he's added right-back to his repertoire, and his tailored role in Fergie's side over the past month has shown us what a specialist he can be too.
Against Tottenham, Sir Alex used him as part of a loose midfield diamond to help wall Gareth Bale in and keep him from roaming inside. Rio Ferdinand covered the ball over the top and Rafael helped double-team him.
The result? No joy for Bale, but a 1-vs.-1 for Aaron Lennon to enjoy against Patrice Evra.
Against Everton, Jones dropped into a far more central role alongside Michael Carrick and man-marked Marouane Fellaini, effectively nullifying the Belgian's threat and contributing heavily toward an easy win.
Then, against Real Madrid, Jones tucked in and chased Cristiano Ronaldo's every move. The Portuguese winger got the better of Rafael, but failed to overcome Jones—so much so that he swapped wings and scored.
Make no mistake, these are three specific game plans by Fergie for three very dangerous players. All three hinged on Jones, and without him Fergie has a lot to consider.
Is there a player on the United roster who can replicate what Jones does?
He needs mobility, tenacity, fearlessness and tactical nous. He needs to be able to play in a variety of positions and not be phased by ending up in strange or unfamiliar areas of the field.
Some may point to Anderson, but his lackluster performance against Reading proved he's nowhere close to full fitness and therefore not able to fulfill this role.
Darren Fletcher is out of the question, while Carrick will be relied upon to anchor the midfield and provide a consistent presence—Fergie can't risk his pace-setter being dragged out of position, and he doesn't have the pace to keep up with him anyway.
A glance at the United roster, and it's easy to see that the only potential player to fulfill the Jones role...is Wayne Rooney.
But do you really want an attacking talisman in such a sacrificial role? It's 1-1, after all.
Don't be reactive, be proactive
The moves to hinder Bale, Fellaini and Ronaldo were reactive decisions by Ferguson. Some managers do that, and in particular Paul Lambert is known for changing his side at will according to the opposition.
Ferguson used to be stubborn and rarely changed his mechanics for anyone, but over the last two seasons he's become significantly more receptive to new ideas.
He may have to abandon that mental growth for now, though, as United's lack of possibilities in this area may dictate he focus on overpowering Jose Mourinho's side.
He's outscored plenty of teams this season already, and that's a product of having an electric offence combined with consistent injury troubles in defence.
Fergie can field his usual attacking side with minimal reactive inclusions. Perhaps Antonio Valencia gets the nod at right-wing for his industry, or Rooney starts the game on the right as he did at the Santiago Bernabeu.
With no viable alternative to Jones, Fergie has to go for it.
Regular readers will know tactical adjustments like the ones Jones has been subject to are what I enjoy the most, but when I tune in to watch the game at Old Trafford I want to see a Red Devils side built to outscore Real Madrid.
If Jones is fit, sticking him on Ronaldo is a wise choice. Rooney's a waste that deep and no one else can do it—not even Anderson.
Bring on the goals.