Liverpool had known for a while that it needed to change. Its front three of Mohamed Salah, Roberto Firmino and Sadio Mané was one of the most potent attacking tridents in the history of the game, their complementary skills elevating each of the three individuals. But all three have turned 30 in the past year; quite apart from concerns that familiarity could breed staleness, it is dangerous to let a team grow old together.
Evolution is perhaps the hardest task facing a manager who would oversee a dynasty. It takes remarkable clear-sightedness to take apart something that has worked and begin to rebuild it.