Manchester United's interim manager Ralf Rangnick has cautioned that the club would require "open-heart surgery" if they are to succeed under Erik ten Hag.
Following the departure of Ole Gunnar Solskjaer in November, the highly-rated German coach has struggled to get a consistent tune out of Manchester United's faltering players.
Rangnick, who oversaw the emergence of RB Leipzig and sister club Red Bull Salzburg, says his time in the Old Trafford dugout has revealed a lot of difficulties.
With the club's late chase for Champions League qualifying resuming on Saturday against top-four opponents Arsenal, the 63-year-old has not held back about the chasm to the likes of Liverpool and Manchester City.
Rangnick's short-term concentration is tempered by a long-term understanding of what United need, despite the fact that the club made a "excellent choice" in choosing Ajax manager Ten Hag as permanent manager.
"I'm quite confident that he's the greatest coach you could hire right now," stated the temporary boss.
"All the other things, as sad as it is and as frustrating as it feels right now for everyone involved – and believe me, this is extremely, terribly frustrating for me because we have only experienced success in the last ten, if not fifteen years, myself as a sporting director and as a football manager.
"However, you can't always look on the bright side in football." We're now on the opposite side.
"However, one of the few positive aspects of what happened is that it is absolutely obvious. It isn't all that tough (to see).To analyze and see where the problems are, you don't even need glasses.
"Now it's just a matter of figuring out how to fix them." It's evident to me that making a few little changes, addressing a few minor faults here and there, and making minor cosmetic changes isn't enough. No, in medical, you'd notice that this is an open-heart procedure, which means there are more things to modify than a few tiny things here and there, which is a positive thing. If this occurs, if everyone recognizes that this is necessary, and if people are willing to collaborate, then it makes sense, and I still feel that it is not necessary to wait two or three years to alter those things.
"Within a year, this may happen." Other teams not far away have demonstrated that it is feasible to achieve success in one, two, or even three transfer windows, rather than two, three, or four years.
Rangnick believes that strong leadership is required to supervise the changes, and that "one single individual as a manager" would not be able to accomplish it.
"You have to have top individuals in all sectors," the temporary leader stated, "and they have to work together in a very close and very dependable way."