United boss Michael Carrick spoke grimly about Dorgu's prospects at the end of January, when United were still attempting to work out how long he would be out for.
He said: "Pat, unfortunately, he's going to be out for a period of time. We're still working through how long that's going to be.
"We'll have to see, it's disappointing, he's had such a big couple of weeks, Pat. We weren't sure whether it was a little bit of cramp or whether it was something a little bit more serious and at the moment it looks a little bit more on the serious note.
"So, it'll be a few weeks for that. How many weeks? We'll have to wait and see. So, that's disappointing for all of us really, and for Pat, he's in such a good place, but unfortunately it is part of football and it's something we've got to work through and get him back as soon as we can."