He received a red card for the first time in his career by picking up two yellows in the first half.
Mata wrote on his blog that he could have avoided the bookings – and says he now has to go through a “bitter experience”.
United are three points off the top four.
Arsenal manager Arsene Wenger says he doesn't feel any more pressure than usual – despite criticism from a number of fans.
They're eight points behind League leaders Leicester following Saturday's 2-2 draw with north London rivals Tottenham.
The Sunday Express reported Wenger will be “invited” to leave if they lose tomorrow's FA Cup fifth round replay at Hull.
In Women's football, Ireland take on Hungary this afternoon in the Cyprus Cup.
Kick off is at 3.30
