The Belgian international has been forced to wear the equipment having suffered a broken nose and a fractured eye socket during a game against Aston Villa in October.
Mignolet, 23, has insisted that the mask doesn't cause him any problems while he is on the pitch.
"The mask doesn't bother me at all, I'm aware of it in the early stages of the warm-up, but once I get going it's fine," he told the club's official website.
"When I went to have it fitted they put plaster over my face to create a mould and make sure it fits perfectly.
"I am very happy with the job the consultant did."
Mignolet joined the Black Cats in July 2010.