Rumours persist that in the January transfer window Arsenal, suddenly realising the benefits of buying established world-class players, will attempt to sign Wayne Rooney; and how desperate might Chelsea be by then for a 20-goal striker? But seeing the mutual delight as he celebrated two goals against Bayer Leverkusen with the Old Trafford crowd last Tuesday night made it difficult once more to envisage Rooney as anything other than a Red of the Manchester variety.
The campaign to keep him is building meanwhile, with Sir Alex Ferguson and David Moyes singing his praises, quite possibly as a prelude to the offer of a new contract. And then there is a man who could have more influence than any other by helping Rooney achieve maximum satisfaction where he has always been happiest – out on the pitch. Robin van Persie wore a broad smile as he rhapsodised about a partnership that brought more than 30 goals and a Premier League title last season and has again looked more potent than any other since resuming business, with five goals between them in United's last two matches.
When Liverpool beat them at Anfield earlier this month, they did not have to cope with the double threat because of Rooney's head injury. Manchester City must do so at the Etihad Stadium today and their success will go quite some way to determining the result.
"We love to play together," Van Persie said. "I think we are both similar players in the way that we are both all-round, we both can drop and both can go in behind. I love to play with Wayne because for me he has it all. As long as we can combine that really well, as long as we work together and try to improve, which we are doing, I think we can go from strength to strength."
Chelsea's desperation to secure Rooney this summer and their subsequent purchase of Samuel Eto'o instead confirmed that they wanted Rooney as an out-and-out striker. That would not have played to his strengths, which United are able to do by using him just behind Van Persie who, as he says, can also drop off into space when necessary.
Rooney has, if anything, improved the quality and variety of his passing game. He can play it either long, as in the assist from his own half for Van Persie's spectacular volley against Aston Villa last season that Sir Alex Ferguson called "the goal of the century", or short as against Swansea this season (see graphic, right), followed by a supporting run.
While some observers alleged selfishness when Rooney jabbed the ball wide in the second half against Leverkusen with his partner square of him, Van Persie was happy to give him the benefit of the doubt: "The ball that just missed me in the second half when it went past me, he wanted to pass, everyone could see that. It is good, it goes both ways. I really think if we can keep on growing, keep on passing each other the ball, we can both end up with a lot of goals this year."
Not just those two either, according to the Dutchman: "Get the wingers involved, because last year I don't think our wingers scored enough. Hopefully this year we can get them more goals, which is really helpful for everyone. So it doesn't only come from Wayne and me, but threatening from all sides.
"Even [Marouane] Fellaini needs to add that as well. He looks very all-round as well to me: he can defend, he's tough, he can make a tackle, he can really find a pass, between the lines going forward, which is very important for us boys up front. He can head a ball, he can help us with set-pieces offensively and defensively."
Moyes, who will not be alarmed by a Manchester derby after involvement in the Glasgow and Merseyside varieties, caused problems for himself in the summer with carelessly chosen words about Rooney being needed "if we had an injury to Robin". What was not as widely quoted was the next sentence: "I want to be able to play the two of them." With Rooney fit and firing, he has that option and is now happy to confirm: "We want to try and make it a partnership where people are saying, 'my goodness, this is tough to play against'. I don't want to exclude Chicharito [Javier Hernandez] or Danny Welbeck, because they won't be able to play in all the games, so I've got to make sure I've got combinations for whenever they are required.
"But a really in-form Robin and a really in-form Wayne Rooney makes it a really difficult partnership to play against, that's for sure. I think if you were coming up against that partnership in the Premier League, you've got a concern."
Vincent Kompany and his City defenders will be well aware of that today, not least because of the 3-2 defeats they have suffered in two of United's last three visits. The scorers? Rooney (2) and Van Persie in the League last season; Rooney (2) and Welbeck in the FA Cup the previous year, when United were three up by half-time with Kompany controversially sent off.
Welbeck could be brought in on the left today but may have to wait with Hernandez for the next big test, Wednesday's Capital One Cup tie against Liverpool, when Luis Suarez could return for the opposition.
Manchester City v Manchester United is on Sky Sports 1 today, kick-off 4pm
Forming a United front
Number of games started together: 27
Number of games played together: 35
Number of goals scored: Overall: Van Persie 36, Rooney 19; Playing together: Van Persie 21, Rooney 17
There have been seven games in which both have scored, for a total of 18 goals.