They said he was undroppable. They were wrong.
Rooney might be United's most prized and precious asset, but Sir Alex Ferguson has always put the needs of his team above the individual at United. After the loss at Everton, Ferguson decided upon a different approach on Saturday and left Rooney watching from the bench.
Ferguson's true justification may never be known. Was he simply making way for Robin van Persie? Was he trying to focus Rooney's motivation after a low-key showing against Everton? Or is there something bigger at play here?
Could that player be Rooney? It may just as easily be Nani, who was left out of the United squad completely on Saturday.
Assuming Rooney does stay, which we must for now, there may be more frustration ahead when he returns from a four-week absence after suffering a deep gash to his knee when he came on as a second-half substitute.
On the early evidence this season, it's hard to see how Ferguson can accommodate Rooney, van Persie and Shinji Kagawa in the same starting lineup. All three are centrally-minded forwards, and United's go-to 4-4-1-1 formation needs only two of them.
Ferguson has some very difficult decisions ahead, but the biggest one can now be avoided until Rooney makes his return. It's not what Ferguson will have wanted, but it will at least ease the burden of trying to placate the kind of player who cannot possibly take well to being in reserve.
Moreover, when Rooney came on it was unclear how his partnership with van Persie might work tactically. Most expected Rooney to operate as the Dutchman's support, but instead he dropped in behind and the result was diluted influence from both men.
They changed roles after a while, but United still struggled for the kind of forward cohesion they found with Kagawa and van Persie in combination.
To that end, Rooney's injury may well have given Ferguson temporary relief from a major selection dilemma. It will also give Rooney a month to consider his new-found status at Old Trafford as a player who is no longer guaranteed a spot in the starting lineup.