The Moroccan was taken off on 70 minutes in Man Utd's 2-2 draw at Everton. The defender was also said to have an ice pack on his knee upon going to the bench.
Rob Dawson of ESPN says that "Noussair Mazraoui picked up a knee injury yesterday at Goodison Park. He is set to undergo further tests on Monday before a decision is made on whether he can play against Ipswich this Wednesday."
It didn't appear anything serious but there was a point when he did go down in the first half clutching his knee. He managed to continue until he was substituted later on.

United will face relegation rivals Ipswich (can't believe I'm saying that 😔) on Wednesday night with Ruben Amorim in desperate need of victory. After the draw at Everton, it meant his side have now gone three games without a win and dropped into 15th in the table after these recent results.
With all the injury issues he's already had, he wouldn't want to lose another player who has been one of United's best this season. More than that, the 27-year-old has been available all campaign as he's only missed ONE game in 24/25 which was the win over Rangers in the Europa League.
To have a player like him who's always there for the manager is invaluable in today's football.
While MUFC are well stacked in defense, they probably can't afford to lose anyone else as the growing injury list now reads:
Altay Bayindir (unknown injury - unknown return date)
Tom Heaton (unknown injury - unknown return date)
Noussair Mazraoui (knee injury - unknown return date)
Lisandro Martinez (ACL - out for season)
Luke Shaw (muscle injury - return date: April)
Jonny Evans (muscle injury - unknown return date)
Mason Mount (thigh problems - unknown return date)
Kobbie Mainoo (muscle injury - unknown return date)
Toby Collyer (knock - unknown return date)
Amad (ankle - out for season)
via Transfermarkt.
As we can see, that is quite a few absentees (10) two of which are season-enders, two of which are backup goalkeepers (how the fuck are they injured?), and two of them are forever injured in Shaw and Mount.
There are also a lot of muscle problems with one of the reasons for this being overuse. While it could also be due to poor flexibility, poor warm-up routine and more, the fact that overuse could be a cause is concerning.
With the amount of football that's being played today and the overreliance of players at United, this is probably a problem that we're not going to get rid of for a while.
Amorim doesn't need any more problems on top of all that he has.
Background Image: Noussair Mazraoui facing injury scare ahead of Man Utd v Ipswich | Creator: James Gill - Danehouse | Credit: Getty Images via SuperSport