Ruben Amorim revealed that Ayden Heaven struggled to speak when he was on the ground after his injury, according to Samuel Luckhurst of the Manchester Evening News.
Further updates on his health will be provided this week.
United fans will be hoping it's not too serious.
Man Utd were in fine form - seeing off Leicester City with ease at the King Power Stadium.
But, the win was overshadowed by a horror injury for youngster Ayden Heaven.
The 18-year-old got in a tangle with Patson Daka at the back post and the game was delayed.
Eventually, a stretcher came onto the pitch to take the defender off, who appeared motionless.
Ruben Amorim gave an update on Ayden Heaven after the 3-0 win.
He said: "It's hard to know because we have to evaluate during the week.
"He already played well against Arsenal and Real Sociedad.
"Today for me was the most difficult game for him because we expect him to relax a bit, but he was so focused."
While his capabilities to lead and inspire will still be questioned, you cannot fault the playing form of Bruno Fernandes this season.
Without his goals and assists it doesn't bare thinking about the situation Man Utd would find themselves in now.
The Portuguese midfielder got a goal and an assist this evening, scooping the man of the match award in the process.
The Red Devils got a win on the road to help bring back a bit more confidence to this squad.
Leicester huffed and puffed but struggled to cause the visitors any real problems.
This offered a big chance for The Foxes, in the end underpinning that they have not got what is needed to secure Premier League safety.
The referee brings the game to a close.
Man Utd have won this game without having to break a sweat.
For Leicester, it seems their fate is unavoidable now.
90+6. It seems pointless for Man Utd to even hold a vote for their player of the season.
Without Bruno Fernandes this season, if you could believe it, would have been considerably worse.
His goals and creativity has kept this sinking ship afloat so often.
Vardy has a late sight of goal but his drilled shot is too close to the keeper and is blocked.
90+4. If anyone was in doubt, the last two Premier League campaigns have really underpinned the gulf between this level and the Championship.
The gulf has never been bigger.
Dominating the league below and winning the title does not guarantee that you can mix it at this level with substantial investment in the squad also.
90+2. Despite the scoreline, this fixture offered a massive opportunity for The Foxes to get back to winning ways.
They welcomed a side in a fragile state to the King Power who are experiencing a nightmare season for a club of their stature.
Leicester really haven't shown the hunger of a team who wanted to seize that opportunity whatsoever.
90. The icing on the cake for the visitors.
Dalot skips past his man and cuts it back to Fernandes on the edge of the box.
His superb strike is always curling away from Hermansen as it clips the inside of the post on its way in.
We are going to have eight minutes added.
88. You have to question the mindset of the Leicester owners.
Steve Cooper was quite vocal about how unprepared they were for life in the Premier League and how desperate he was to bring in players.
They have banked upon Vardy scoring enough goals to keep them up and is a crazy notion to ask of a 38-year-old at this level.
86. Zirkzee lands awkwardly after challenging for the ball.
In the modern game you don't know whether you should be worried or prepare yourself to be annoyed.
So many players make a meal out of the slightest of contact and moments later they are sprinting around like they have received some miracle cure.
84. Amorim makes some more changes to keep his side fresh.
Hojlund still wont see out a full match despite his goal tonight.
Not that it will bother him right now, he will be so relieved to finally get that monkey off his back.
Obi comes on for a cameo to replaced him.
82. The travelling fans will see this as a worthwhile trip having seen such a comfortable win for their team.
Ruben Amorim will be wanting his players to keep focus and protect their clean sheet until the end of this match.
They will have much tougher tests than this blunt Foxes' attack but mindsets are key and not conceding tonight will no doubt boost that confidence.
80. As a result of some of their recent defeats, you can see van Nistelrooy has instructed his team to get ten players behind the ball whenever they lose it.
The problem with that is, if they win it back, there is not out-ball as Vardy is left so isolated up front.
You could have the best striker in the world up front but he is going to pose no threat at all going up against a back four all on his own.
78. That missed chance is exactly why Brighton have farmed him out to Leicester on loan.
The youngster needs game time to get more experience at this level and improve his game.
Then he may have had the foresight in that situation to dummy an effort to cause de Ligt to commit before shooting.
76. What a chance for Leicester to get back into the game.
Vardy runs clear but slows his run for support to catch up.
With two defenders in front of him, he threads a superb pass in between them to pick out Buonanotte.
He shoots but de Ligt slides in makes a goal-saving block.
The Foxes have created two big chances in this game, their faiilure to convert is why they are heading to defeat once again.
74. This has been such a disappointing season for The Foxes' fans.
You can take a relegation but you want to it the right way and go down fighting. making your opponents scrap hard for every point they take from you.
This has been far from the case for Leicester, it has been a bit like Burnley and Sheff Utd last season who just looked out of their depth at this level.
72. It is very true that there are usually always positives to be found in every situation.
Despite struggling with injuries at the moment, it is a very good time to be a young player at Man Utd.
Amorim's hand is being forced to blood the inexperienced academy players which is giving them a real opportunity to impress.
70. Amorim opts to make some changes immediately after the goal.
Ugarte, Eriksen and the goalscorer Garnacho are brought off.
They are replaced by Casemiro, Zirkzee and Amass.
68. If you write it, it will come.
After the previous post Garnacho seems to address that very problem.
No chance of this one being chalked off as the Argentine winger gets back to his scoring ways.
His last goal was in the reverse fixture at Old Trafford.
66. Even if they do end up winning this game, Ruben Amorim will not laud his side with positives when they analyse the performance.
Dominating the ball but failing to put the game to bed has been a reoccurring theme that has cost them wins this season.
It is almost as if they go into auto-pilot when leading with no drive to turn the screw and see of their opponents.
64. Having replaced their manager to change their fortunes earlier in the season, it has not panned out how the owners wanted.
That will of course raise the unavoidable conversation amongst fans wondering whether Steve Cooper could have done better.
It is the game of Russian roulette that you play changing your leader during the season, it is not looking like ending in a positive way for Ruud van Nistelrooy.