Carrick is struggling with an Achilles injury that will see him miss a crucial run of fixtures for United.
“We’ve had a little setback with Michael Carrick,” said Ferguson.
“He’s out for three weeks with an Achilles problem, maybe a month at most.
“It has been bothering him for a few weeks now, so we sent him to a specialist in London yesterday and he had an injection.
“We are hoping that settles it down. We have been considering what we should do about it. The best thing is to get it treated and out of the road now.”
