The 20-year-old arrived from Liverpool in an £18m deal that could rise as high as £23.5m depending on instalments.
"Everyone is under consideration (for Man United tomorrow), he said.
"You have got to look at it from Rhian's point of view, from an experience point of view in a team that is struggling.
"He came late in the window and is new in the club and is working extremely hard.
"People want to make quick judgements on people and that's the business we are in.
"When things go well they are all incredible and he should be playing for Real Madrid and managing Real Madrid and when they don't it's how did they get a career in football and I wouldn't let him manage my local Co-op, but that's how it is.
"There's a story to every situation.
"From Rhian's point of view he's a young player, I don't think there's any fault of his, if there's any fault it's the team and mine not him, because he's going to be fine and we will be fine in the long run.
"There's a reason that I have not just signed him for the short term and people lose a little bit of form and don't always get off to a flying start."