Carrick has failed to secure a Premier League victory as United manager since August 30. And the club have been tipped to pursue a change of managers, despite only appointing Carrick to the role permanently in the summer.

Redknapp has argued that former Newcastle boss Eddie Howe, currently out of work, and present Aston Villa head coach Unai Emery would represent the sole credible options for the United position should the club opt for change.

"There are only, I think, two runners," Redknapp told Sky Sports. "Listen, Michael Carrick is still in the job, so it's unfair to be saying it.

"But if that's the case, if this doesn't improve, it's inevitable that he's going to lose his job. It can only be him [Emery] really and Eddie Howe."

"Julian Nagelsmann has done pretty well in Germany," Redknapp said. "I think he started off his career so good... last few years, not quite so good, obviously with Germany at the World Cup.

"I can only really see him [Emery]. It depends, does he want to leave Aston Villa? He's got a project, he can do what he likes there, he's running the club, whatever he says goes.

"With his abilities, he would probably be the only one that I would trust to be able to do it.

"I don't believe anyone else is just going to go in there with a manager and an assistant and change it. There are so many things behind the scenes that need to change."