Harper suffered a nasty shoulder injury at Everton on Saturday.
Hughton said: "Tim Krul has come in before and adapted very, very well. He is a young keeper of high ability and I certainly have no worries about him and him performing.
"But we will have to assess it once we are made aware of the extent of Steve's injury.
"Tim is in the squad for the Chelsea game and I have absolutely no worries in putting him in."