We've covered the reasons Rooney is likely to be off before, but here's a brief recap and update as reports come in of an imminent bid from Chelsea.
Deep down, it's clear that United know that Rooney's £250,000-a-week contract is not providing value for money. If they believed it was, there would be no press-posturing and no delays in getting it sorted out. Instead, United's casual approach to the expiry of his contract confirms that they are at least open to the possibility of letting him leave. Rooney clearly won't want to take a wage cut - so if anyone else wants to match his wages, then he'll be leaving. It is that simple.
2. David Moyes
We've been told they've now kissed and made up, but there's little doubt that the two have a strained relationship, and looking at Rooney's autobiography, simply seem to rub each other up the wrong way. Moyes will know that selling Rooney now will look a lot better from a PR perspective than a fall-out later down the line.
3. Alex Ferguson
With Ferguson's criticism and knife-in-the-back at the end of last season, it's not only clear that United's previous manager has given his replacement a clear run to make a sale, but also that he's not too keen on keeping Rooney around himself. He may no longer be sitting in the dugout, but the significant influence he still wields at Old Trafford makes things even more difficult for Rooney to stay.
4. United's squad
Rooney simply isn't as important to Manchester United anymore. They have one superior centre-forward in Robin van Persie as well as two very good ones in Javier Hernandez and Danny Welbeck, with Shinji Kagawa and potentially Thiago available to take the position in the hole. United have never been in a better position to make do without him.
5. His name
The name of Wayne Rooney still carries a lot of weight, and that means something. Barcelona and Arsenal fans have both been hugely excited about the prospect of signing him, which means that he is a marquee signing with a prestige value that is hard to find. That means that there should be plenty of suitors feeling ready to meet the cost.
In addition to all this, the Daily Mail - usually fairly well-sourced with regards to United - report that Chelsea are set to make a considerable offer for Rooney. We know Jose Mourinho is a big admirer and also that Chelsea desperately need someone capable of playing as a lone forward. If United can't find a buyer on the continent - they may well do, and they'll probably hold out in hope of finding one - then it makes sense for all three parties. When that happens, a deal is rarely far away.