David Moyes had to contend with Wayne Rooney wanting out during his first summer in charge in 2013 and Ole Gunnar Solskjaer faced his own headaches with Romelu Lukaku six years later. Any manager will tell you that an unsettled star is among their worst nightmares and the reality players do not come much bigger than Ronaldo. This is not an issue that can be brushed under the carpet.
How Ten Hag handles the situation will be as intriguing as it is important and give us an early insight into his man-management but there is no textbook in such instances. Questions about Ronaldo are likely to dominate his first press conference in advance of his first game against Liverpool in the Thai capital on Tuesday, when Ten Hag will quickly discover just how incessant the interest level is in the club and its most famous player, not least in Asia where the hysteria that greets United can take some digesting. And the longer Ronaldo remains away, the more persistent the questions are likely to get.
Gary Neville, the former United captain, spotted a possible crisis immediately when news first broke that Ronaldo wanted out but his pleas for the club to deal with the matter swiftly and decisively and not let it turn into a saga are said easier than done.
Perhaps Ten Hag will be able to talk Ronaldo round but the player is unlikely to have asked for a move on a whim and, unless an offer that is acceptable to all is forthcoming quickly, this particular episode has the potential to run and run. Chelsea have an interest and Napoli have been linked but Ronaldo’s £40 million a year wages are likely to be a problem for any suitor and, even if United relent from their current stance that the 37-year-old is not for sale, he would also command a transfer fee.