The 37-year-old is closing in on his 200th appearance.
Harper came off the bench against Bordeaux on Thursday night to make his 195th appearance for United.
Alan Pardew: “Our fans love him, and so do we.
“He’s a very, very important player – he’s been brilliant for us.
“Harps has come out and said the blow of not getting the No1 jersey hurt him.
“I think it hurt his professionalism and his pride, and you’d expect that. I wouldn’t have expected a man of his nature not to. He’s a big character.
“This year he’s come back saying ‘OK, I’m going to fight for my place’.
“What’s happened is that it’s fell his way, and he’s taken his opportunity.”