Manchester United could be without midfielder Casemiro when they play Arsenal next week.
On Sunday, Arsenal extended their lead in the Premier League after a 2-0 win over rivals Tottenham.
This result has made the Gunners eight points above the defending champions Manchester City, with Newcastle and United winning.
Indeed, United have also been in extraordinary form this season, achieving their 9th consecutive win against Man City.
If United beat Crystal Palace at Selhurst Park on Wednesday night as expected, next Sunday's game with the Gunners could be decisive in the title race.
However, United may be missing an important player against Arsenal.
United could have big Brazilian midfielders Casemiro and Fred in their match against Arsenal.
If both players receive a booking against Crystal Palace they will miss the Gunners game.