#4 Matic continues to be in poor form
The Serbian looks a completely different player this season. His loss of form has been one of the main reasons for United's lack of defensive discipline. Last season, Matic had finished the season with 70 tackles, 16th among all the midfielders in the Premier League and had attempted 2601 passes, 6th highest in the league.
This season, Matic has just 15 tackles so far, he's not even among the top 40 in the league and has attempted just 617 passes, putting him in the 34th position among the top passers so far. Incidentally, Fred has 14 tackles and Luke Shaw has 613 passes!
Against Palace too, Matic could not dictate the play and his poor form has affected the players around him. While the defense has been borne the blunt of his misdeeds, Pogba has been suffering too, for lack of support. As such, now is the time for change, if Mourinho finally acknowledges it. Fred, Herrera or even Pereira would be a far better choice and perhaps a break would do the Serbian a world of good too.