After an incident that occurred at Old Trafford against Bournemouth, Manchester United striker Zlatan Ibrahimovic could find himself retrospectively punished for up to three games.
Tyrone Mings seemed to have stepped on the head of the Swede, which lead to his retaliation - a vicious and deliberate elbow.
Referee Kevin Friend missed both incidents and failed to send off either player, but the FA could step in.
If the 35-year-old were to be sidelined, he would miss the FA Cup game with Chelsea, and Premier League meetings with West Bromwich Albion and Middlesbrough.
"I went for the ball and it was unlucky he jumped into my elbow. But it was nothing on purpose... I hope he's not injured," Ibrahimovic told MUTV.
Mings denied deliberately stamping on Ibrahimovic, although Sky Sports pundit Jamie Carragher described his action as "disgraceful".
"Not at all. I would never do that. That's not in my game. Hard and fair is how I like to tackle but off the ball stuff like that isn't in my game," Mings said.
"He (Ibrahimovic) is who he is, he's a good player, he's a physical player. I knew what sort of battle I was going to be in for coming here. And that's what we had all day, it was a battle," he added.
"There was maybe an elbow when the ball came in after, I didn't see it, I felt it."
Ibrahimovic was denied several times by inspired Bournemouth goalkeeper Artur Boruc who also saved his weak second-half penalty to complete a rare bad day for the Swedish striker in his first season in England during which he has scored 26 goals.
Messi has participated in 42% of Barcelona's goals
With yet another masterful performance against Celta Vigo, Lionel Messi has consolidated his status amongst LaLiga's top attacking threats in the 2016/17 season.
The Argetinian has scored a staggering 38 goals and delivered 13 assists in only 37 matches among all competitions.
Since the Blaugrana have beaten opposing goalkeepers 122 times thus far, Messi has been directly involved in 42.8 percent of all goals.
Moreover, the 29-year-old leads the ranking of LaLiga players who have managed to both score and assist in the same match, having achieved the feat nine times.
Luis Suarez and Celta's star Iago Aspas are his closest competitors with seven of such matches apiece.
Fellow Barcelona forwards Arda Turan and Neymar also appear near the top of this type of list, and so do Atletico Madrid's Kevin Gameiro, Antoine Griezmann and Angel Correa.
However, according to this particular statistic, Real Madrid's offensive weapons lack versatility, as only Karim Benzema shows up high in the ranking.
Luis Enrique: I have faith Barcelona will put up a fight vs. PSG
Immediately after putting in what most will likely consider Barcelona's best performance of the season with a 5-0 win over Celta, Luis Enrique will be asking himself if his squad can repeat the feat midweek against Paris-Saint Germain.
Trailing by four goals in the Champions League is a deficit that has never been overturned, but Saturday night's match at the Camp Nou will serve as a test run to see if the Blaugrana can at least try to achieve the seemingly impossible.
"I have faith that Barcelona will put up a fight vs. PSG," the Asturian coach said. "I know what Wednesday's match means.
"I've never analysed a match as much as the first leg in Paris."
While some are trying to draw a parallel between a Barcelona victory over Celta and a hypothetical one over PSG, the coach doesn't believe the match prepares his side for what is to come.
"In terms of football, the two matches won't be anything alike because PSG don't man-mark like Celta," the Barcelona boss pointed out. "But against Celta, who are always very difficult to play against, I saw the team enjoying themselves.
"It's the best we've ever played them."
Nonetheless, it is the PSG showdown that has occupied the coach's energy ever since the first leg in Paris, and the Blaugrana tactician has lost sleep trying to find the way to turn it all around.
"It isn't normal for us to be so thoroughly outplayed," he continued. "Barcelona are going to take risks, lots of them.
"We want to create an atmosphere that will allow the Camp Nou to help us even more than they usually do."
Zidane: I'm very happy with Benzema's performance
Two goals from Karim Benzema helped Real Madrid to a 4-1 away win against Eibar in LaLiga this weekend, answering criticism that the France international hasn't been performing to par this season in domestic action.
The Frenchman opened the scoring with an opportunistic close-range finish, before making it 2-0 by turning home a wicked free-kick delivery from James Rodriguez.
"I am very happy with his performance, for his goals and for the other things he did in build-up play," Zidane explained post-match.
"I am happy with the great game that he's had, but for the ball to get to him the rest of the players have to do well and they did."
Zidane was pleased to get back to winning ways after a recent 3-3 draw with Las Palmas, and views this three points as a quick turnaround of form.
"I am happy with the reaction. In a season, there are lots of different moments, a team can't always play well. We have played very well, with intensity. We came in with a high tempo and this is important.
"Real Madrid started very well, we scored three goals in half an hour... we knew that it would be a tough pitch to play on. We played a serious game, always respecting our opponent."
Marco Asensio popped up with the fourth goal on a great afternoon for the youngster, which Zidane was keen to recognise, and always had a few words of praise for Luka Modric.
?"He [Asensio] had a great game. It isn't easy to not play a lot and then need to play as if you have every three days. I believe that he is very happy with his goal and for the performance he's put in.
"Luka is a very important player for us. He manages the games well, he knows when to slow it down and when to speed it up. He is a key player for the team," he said.
James Rodriguez: Eibar victory gives Real Madrid confidence for rest of season
Having helped Real Madrid to a solid 4-1 win away to Eibar in LaLiga, James Rodriguez spoke of how the resounding scoreline will help Los Blancos regain some momentum ahead of key games.
Travelling to Napoli on Tuesday for a Champions League tie, the reinstated league leaders then face Real Betis and Athletic Club in domestic action.
"4-1 was a fair scoreline and it gives us confidence for everything that is to come this season," said the attacking midfielder to reporters.
"[Napoli] have an impressive stadium but if we concentrate and go in with a lot of intensity, then we'll be on the right track."
After reports of another team meeting with coach Zinedine Zidane in the build-up to Saturday's game, Rodriguez dismissed any notion of an unsettled environment for either himself or the Real squad.
"I am happy, I always want to help the team to win and we have done well [against Eibar]," he noted. "It's not about ourselves as individuals, but as a group.
"If the headlines are positive, the team plays well.
"I'm not going to say anything about [team meetings], we're still united as we always were. There's a healthy atmosphere around the squad and we want to keep it that way."